The MacArthur Study Bible (NKJV) states of Psalm 110.1, "Using this passage, Christ also declared His deity in the Gospels (Matt. 22:44; Mark 12:36; Luke 20:42-43) by arguing that only God could have been lord to King David." Ron Rhodes puppets this argument also. In his Reasoning from the Scriptures with Jehovah's Witnesses on p. 162 he writes: "Ask the JW's: Did you know that the same word used for "Lord" (adonai) in Ps. 110:1 of Jesus Christ is also used of the Father numerous times in Scripture…?" The argument is basically a lie, because the word in Psalm 110 is not adonai, but adoni, which is never a reference to Deity and always (195 times) a reference to someone who is not God.

In The Doctrine of the Trinity -- Christianity's Self-Inflicted Wound (p. 47) Anthony Buzzard writes:

"Psalm 110:1 provides a major key to understanding who Jesus is. The Hebrew Bible carefully distinguished the divine title adonai, the Supreme Lord, from adoni, the form of address appropriate to human and angelic superiors. Adoni, 'my lord,' 'my master' on no occasion refers to the deity. ...The difference is one which depends on the Hebrew vowel points. It is clear that the distinction between adonai and adoni has been faithfully preserved since ancient times. The translators of the LXX in the 3rd century BC attest to a careful distinction between the forms of adon used for divine and human reference by translating adoni as ho kurios mou, 'my lord.'"

Finding this very interesting, I decided to test it out myself. Below you will see all, if not most evidences of adoni straight from your own Bible. I will start off with the King James Version (KJV) and then split off with other popular versions. The results are quite telling:

AV Version:

Gen 23:6  Hear us, my lord: thou art a mighty prince among us.
 
Gen 23:11 Nay, my lord, hear me: the field give I thee.
 
Gen 23:15  My lord, hearken unto me: the land is worth four hundred shekels of silver; what is that betwixt me and thee? bury therefore thy dead.

Gen 24:12  And he said O LORD God of my master Abraham, I pray thee, send me good speed this day, and shew kindness unto my master Abraham.

Gen 24:14  thou hast shewed kindness unto my master.

Gen 24:18 And she said, Drink, my lord: and she hasted, and let down her pitcher upon her hand, and gave him drink.

Gen 24:27 Blessed be the LORD God of my master Abraham, who hath not left destitute my master of his mercy and his truth: I being in the way, the LORD led me to the house of my master's brethren.
 
Gen 24:35 And the LORD hath blessed my master greatly

Gen 24:36  And Sarah my master's wife bare a son to my master when she was old: and unto him hath he given all that he hath.

Gen 24:37 And my master made me swear

Gen 24:39 And I said unto my master, Peradventure the woman will not follow me.

Gen 24:42 O LORD God of my master Abraham

Gen 24:44 my master's son

Gen 24:48 my master Abraham

Gen 24:49 deal kindly and truly with my master

Gen 24:65 And the servant had said, It is my master

The rest I will present in chart form comparing different versions:
 

N/T= "Not Translated"

All the above scriptures use adoni, and none of them refer to Deity. It is interesting that it is this form of "lord" that is used of Jesus, in Psalm 110:1. There are two other scriptures that are often applied to Jesus, and these are highlighted at Joshua 5:14 and Daniel 12:8. Notice how the highly trinitarian CEV (Contemporary English Version), uses the term "lord" only once, and it is at Ps 110:1. Others have capitalized "Lord" at Psalm 110:1 knowing that it applies to Jesus, and others have felt the need to do so also at Joshua 5:14, and Daniel 12:8, as these might also apply to a preexistent Christ.

The following are all the occurrences that I have found in the LXX of TW KURIW MOU, which again, bear out interesting results, in that this expression is not used for YHWH (as the following, in brackets, gives the referent).
 
Psalms 109: 1(110:1) O KURIOS TW KURIW MOU
"The Lord said to my lord, 'Sit at my right hand..." Pietersma (David, speaking)

Psalms 153:1 KAI TIS ANAGGELEI TW KURIW MOU AUTOS KURIOS AUTOS EISAKOUEI
"But who will report to my lord? The Lord himself, he listens." Pietersma (David)

1 Chronicles 21:3 KURIOU MOU TOU BASILEWS BLEPONTES PANTES TW KURIW MOU PAIDES INA TI ZHTEI O KURIOS MOU
"may the eyes of my lord the king see it" Thomson (Joab speaking to David)

1 Samuel 24:7 TW KURIW MOU TW CRISTW KURIOU EPENEGKAI CEIRA MOU EP' AUTON OTI CRISTOS KURIOU ESTIN OUTOS
"And David said to his men, The Lord forbid it me, that I should do this thing to my lord the anointed of the Lord" Brenton (Saul)

1 Samuel 25:26 KAI NUN KURIE ZH KURIOS KAI ZH H YUCH SOU KAQWS EKWLUSEN SE KURIOS TOU MH ELQEIN EIS AIMA AQWON KAI SWZEIN THN CEIRA SOU SOI KAI NUN GENOINTO WS NABAL OI ECQROI SOU KAI OI ZHTOUNTES TW KURIW MOU KAKA
"those that seek evil against my lord, become as Nabal" Brenton (David)
 
1 Samuel 25:27 TW KURIW MOU KAI DWSEIS TOIS PAIDARIOIS TOIS PARESTHKOSIN TW KURIW MOU

1 Samuel 25:28 POIHSEI KURIOS TW KURIW MOU OIKON PISTON OTI POLEMON KURIOU O KURIOS MOU POLEMEI

1 Samuel 25:30-31 KAI ESTAI OTI POIHSEI KURIOS TW KURIW MOU PANTA OSA ELALHSEN AGAQA EPI SE KAI ENTELEITAI SOI KURIOS EIS HGOUMENON EPI ISRAHL KAI OUK ESTAI SOI TOUTO BDELUGMOS KAI SKANDALON TW KURIW MOU EKCEAI AIMA AQWON DWREAN KAI SWSAI CEIRA KURIOU MOU AUTW KAI AGAQWSEI KURIOS TW KURIW MOU KAI MNHSQHSH THS DOULHS SOU AGAQWSAI AUTH
 27.  And now this present which thy servant hath brought unto my lord, let it be given unto the young men that follow my lord. 28.  Forgive, I pray thee, the trespass of thy handmaid: for Jehovah will certainly make my lord a sure house, because my lord fighteth the battles of Jehovah; and evil shall not be found in thee all thy days. 30. And it shall come to pass, when Jehovah shall have done to my lord according to all the good that he hath spoken concerning thee, and shall have appointed thee prince over Israel, 31.  that this shall be no grief unto thee, nor offence of heart unto my lord, either that thou hast shed blood without cause, or that my lord hath avenged himself. And when Jehovah shall have dealt well with my lord, then remember thy handmaid. (David)] ASV

2 Samuel 1:10 AUTOU KAI ENHNOCA AUTA TW KURIW MOU WDE
"I have brought them hither to my lord." Brenton (David)

2 Samuel 18:28 EN TW KURIW MOU TW BASILEI
"against my lord the king" Brenton (David)

2 Samuel 19:29 TW KURIW MOU TW BASILEI
"before my lord the king." Brenton (David)

1 Kings 18:13 H OUK APHGGELH SOI TW KURIW MOU
"Has it not been to thee my lord" Brenton (Elijah)

Isaiah 36:8 TW KURIW MOU TW BASILEI
"make an agreement with my lord the king of the Assyrians" Brenton (self-explanatory)

Judith 11:5 KAI OUK ANAGGELW YEUDOS TW KURIW MOU
"I will say nothing false to my lord this night. NRSV (Holofernes)

Judith 12:14 EIMI EGW ANTEROUSA TW KURIW MOU OTI PAN O ESTAI
"Who am I to refuse my lord? NRSV (Holofernes)

Genesis 24:14 TW KURIW MOU ABRAAM *
"my master Abraam." Brenton (self-explanatory)

Genesis 24:36 KAI ETEKEN SARRA H GUNH TOU KURIOU MOU UION ENA TW KURIW MOU
And Sarrha my master's wife bore one son to my master after he had grown old; and be gave him whatever he had. Brenton

Genesis 24:39 EIPA DE TW KURIW MOU MHPOTE OU POREUSETAI
And I said to my master, Haply the woman will not go with me. Brenton

Genesis 24:44 TW KURIW MOU ABRAAM
and she shall say to me, Both drink thou, and I will draw water for thy camels, this shall be the wife whom the Lord has prepared for his own servant Isaac; and hereby shall I know that thou hast wrought mercy with my master Abraam. Brenton

Genesis 32:5 KAI ENETEILATO AUTOIS LEGWN OUTWS EREITE TW KURIW MOU
And there were born to me oxen, and asses, and sheep, and men-servants and women-servants; and I sent to tell my lord Esau, that thy servant might find grace in thy sight. Brenton

Genesis 32:6 KAI APESTEILA ANAGGEILAI TW KURIW MOU
And there were born to me oxen, and asses, and sheep, and men-servants and women-servants; and I sent to tell my lord Esau, that thy servant might find grace in thy sight.
Brenton

Genesis 32:19 APESTALKEN TW KURIW MOU HSAU KAI IDOU AUTOS OPISW HMWN
Thou shalt say, Thy servant Jacob's; he hath sent gifts to my lord Esau, and lo! he is behind us.
Brenton (18)

Again, we see that every time TW KURIW MOU is used, it is used in reference to lesser beings, never to deity. Is it any wonder that the Bible says:
"The Lord God will make him a king, as his ancestor David was." Luke 1:32 TEV

Sit at My Right Hand:

To better understand Jesus inferiority to YHWH (Jehovah/Yahweh), we must look at the phrase in Psalm 110:1, "Sit at my right hand." Many say that this implies equality, but can this be proven scripturally? The NIV Study Bible has this to say:
 
"The place of honor beside a king (see 45:9; 1 Kings 2:19); thus he is made second in authority to God himself."
 
It is interesting that the 2 scriptures used by the above study Bible mention queens. Since trinitarians argue that Psalm 110:1 affirms Jesus' deity, are then we also to assume that the above 2 scriptures affirm the queen's kingship?

The Conclusion:

"...those who actually companied with Jesus found him fully and naturally a man. He did not seem to them to be some indeterminate person from some halfway land in which human and divine were intermingled; he did not seem to them a kind of Greek demigod, neither fully human or fully divine; he did not seem to them to be so divine as to be inhuman."  (William Barclay, Jesus As They Saw Him, p.15).

We can see with the frequent references to Psalm 110:1, that the early Christians did not expect 1/3 of the Trinity to appear. What they did expect was a man, an agent of YHWH.

Psalm 110:1 is quoted by:

Jesus: Matt. 22:44; Matt. 26:64; Mark 12:36; Mark 14:62; Mark 16:19; Luke 20:42, 43;  Luke 22:69; Rev 3:21.
 
Peter: Acts 2:33-34, Acts 5:31. I Pet. 3:22.

Stephen: Acts 7:55-56.

Paul: Rom 8:34; I Cor. 15:25; Eph 1:20; Eph 2:6 Col 3:1; Heb 1:3; Heb 1:13 Heb 8:1; Heb. 10:12-13; Heb. 12:2.

"For David ascended not into the heavens: but he saith himself, The Lord said unto my Lord, Sit thou on my right hand, Till I make thine enemies the footstool of thy feet. Let all the house of Israel therefore know assuredly, that God hath made him both Lord and Christ, this Jesus whom ye crucified." (Acts 2:34-36, ASV)

 Original source: http://www.4yhwh.com/bible-files/adoni.htm