Get a penis tatoo'd on your head, start a new trend :p
On a more serious note, I would recommend waiting till your 25 (which I think should be the legal age before giving consent to another person permanently mutilating your body for the rest of your life).
If you do decide to go ahead with it, get something small and in a place easily concealed so if you decide afterwards you dont like it, you wont be stuck with something you cant cover if you need too.
I know a few people who have had tatoo's, and all of them have regretted it in some fashion. One had a panther which covered his entire lower arm, but to be honest it looked shit (though I wouldnt tell him that) and I guess he has never been totally happy with it as has had to go back and have multiple adjustments made to it, and now it looks like a big colourful mess that you can hardly tell what it was. I reckon if something came up to him with some magic gel that could remove it, he would probably bite their hand off and be willing to pay more for that than he did the tatoo itself.
I cant say I have ever seen someone with a tatoo which I thought to myself afterwards 'wow, thats cool' it usually more always along the lines of 'what the f**k were you thinking?'
The best way to find out if you can trust somebody is to trust them.
Ernest Hemmingway
