Okay, this may sound a little strange, but...
Try looking up sites that sell rubber stamps for crafts and card making. There's a ton of them out there. The two that just popped into my head are
www.embossingarts.com and
www.heroarts.com. They have tons of designs with different scenes, animals, some cartoons, etc. It might help. Of course, if you want one of the tattoos that could never be mistaken for anything but a tattoo design, you won't find one on those sites. But if you want something relatively cute, then this is a good idea. The first tattoo I got came from a stamp catalog. The really cool thing was that I could cut the image out, stick some tape to it, and try to decide where exactly on my body I thought it looked best. Now I know that sounds wierd!
But trust me, it worked very well.