I'd like to do something with a glass tile mosaic. I've seen some beautiful backsplashes on this site and elsewhere, but I'm not sure how to get one of my own. Do I have to come up with the pattern? Does it come already in a pattern?

And do you think it's a do-it-yourself job, or do you recommend hiring someone? With so many small tiles, it seems like there is more room to screw up.