I would have to say that Harley riders have been getting Harley-related tattoo’s since the early 1950’s. I would say that fifty years does not a fad make.
Be careful what you choose though. A friend (skinny white guy) got a “Casper” type ghost on his upper arm a looong time ago and has been known as “Spook” since. There were times when someone would call him across a crowded bar and often some claifications were called for.
Amusing now. Back then, not so much.
I’ve always thought that the spiral of a nautilus shell was the most beautiful thing in the world. Unfortunately, my brain’s farted and I can’t remember what it was called. Logarithmic spiral? Bernoulli? I remember the guy who came up with it wanted one on his gravestone, but the carver screwed up and gave him a plain old concentric spiral.
Unfortunately, I suspect that it wouldn’t look near as perfect when applied to skin. 
Well, maybe if you get Calvin peeing on a Copyright symbol…
This is completely off-topic, but I decided a while back that if I ever have a pet again I’m getting two cats: a white one named Cracker and a black one named Spook. It would be the least politically correct thing I’d ever do in my life, but I think 15+ years of amusement would be worth it!
Golden spiral? Or Fibonacci (sp.) spiral?
Nerd joke!!!
bubastis, Tatoo parlors usually have posters and/or books with hundreds of designs to consider. Since you’ll want to check out the place you’re thinking of using, drop by and look around and talk to the people who work there.
I have a flower on my ankle, and as others have suggested, before I made it permanent I used a temporary tatoo for a couple of months. I was so thrilled with the temporary one that I knew I was ready for the real thing.
If I get a second tatoo, it will be a single black eighth note on my shoulder.
Did someone mention a music-related tattoo? 
I have a G-clef on my ankle. 
And you can then change your screen name to Quaver.
How about something astronomical? Mars, a star, a constellation, a meteorite, a comet?
I was thinking about this some more and realize I forgot to mention that I have done several designs for friends. We would sit and talk, sometimes over a couple drinks, and they’s tell me what symbols were signifigant in their lives. One lady I knew had a heart, within a wall that was crumbling, with and eye (to the soul) and we came up with a “flash” tha we made several copies of and she took home with a girlfriend and did different color schemes. I asked that she tape them up as I said before and after 3 weeks she decided on one. Turned out great and she is wearing it today. Another guy talked of special times with his now-deceased father that included a baseball, bat, a glove, an American flag, and a hotdog. They were the happiest times of his life and it came out great! Another guy wanted an arm band all the way around his upper arm and we did a series of Hebrew letters of his childrens names.
I don’t recommend these to you, and maybe not even a standard “flash” in a shop. Think of meaningful symbols in your life, write them down whether they are connected or not, and talk to someone you know who can draw. They need only have meaning to you.
Also, there are some really great Tattoo magazines with pictures you won’t believe. I suggest never copying someones tattoo but an element of one here, a piece of one there, you get the idea.
If this ends up happening, I hope you will let us know what you did.