Have you heard of Water Marbling? I see it most everywhere - the makeup gal at Mac, the cute college girl in my pilates class, the cashier at The Mixx.
It's like an accident to me - I can't NOT LOOK when I see it on someones nails. Like stare and try to figure it out. It's totally fascinating.
It seems to be a pretty complicated process that once you do a few times you get the hang of, but I barely have time to shower each day so I don't think I will be adding this to my to-do list anytime soon. Plus it seems a little young to me. I do think it looks pretty cool though, especially that last image. It's very arty.
The gals over at Hey Nice Nails have a popular tutorial on it. While you're there, check out the INSANE things they do with their nail polish. Connoisseurs if you ask me.