fret not, distressed damsel!
i am in your opposite situation - i am shy around girls.
take solace in the fact that you are not alone - there are guys in your predicament as well.
easy solution = there is none. painful, but true.
if you want to not "look like a snob"...i don't know what actions/language you're taking/using, but try something simple first.... try just being quiet. ok, so you freeze... don't frown, or glare, or whatever, if you do... smile a tiny shy smile - if you are interested. if not, let them know that nicely - a plain "it was nice meeting you, thank you anyway" (or something similar) should suffice, then go about what you were doing. ask your friends for help. they should understand.
and, like i said, if it was ME, i would be too shy to come over to you anyway haha i mean, i'd smile. i might even turn red. hahaha...but, you are not alone in your shyness.
you could also try talking to a guy when there aren't any distractions....and a very simple "hi" will break the ice! but it's saying that first "hi" that can be the most terrifying thing! i know... ;) you could always give them a compliment, or if you are familiar with something on their person (band t-shirt, etc) you could always use that as a starter...
:) best of luck to ye!