I don't like tattoos. Though I am a Graphic Artist, I personally think tattoos mar the beauty of the human body. However, both my nephews have tattoos (plus, my niece has her tongue pierced and her lower lip pierced), and a friend of mine, who is a strong Christian, has both arms covered in tattoos (though he got them before he was saved, and he regrets the tattoos now).
Leviticus 19:28 even says, "Do not cut your bodies for the dead or put tattoo marks on yourselves. I am the Lord." However, this was a command from God, specifically to the Israelites, after they had left Egypt as former slaves. They were going to the Promised Land, which was Canaan. Canaan was currently occupied by pagans who practiced child sacrifices and other horrendous acts. God did not want His followers---His people---to disfigure their bodies after the manner of the pagans. Lacerations and disfigurement were common among pagans as signs of mourning, and to secure the attention of their deity. God wanted His people to be separate from these pagans.
Not only that, but the verse before (verse 27) says, "Do not cut the hair at the sides of your head or clip off the edges of your beard." This is a prohibition still followed by orthodox Jews today. Yet, this verse demonstrates that these commands were for a specific people. I don't know of any Christians who believe that if you cut your hair, you are sinning. In fact, when I was attending Bob Jones University, they had a rule that your hair could not touch your collar or your ears, and your bangs had to be at least an inch above your eyebrows. I was told that someone actually used the verse mentioned above (or possibly a similar verse) to try to keep from getting a haircut! However, I think they still made him get his hair cut.
Many Christians today would consider a tattoo parlor an ungodly place. Yet here is a guy who apparently uses the art of tattooing for the glory of God: