Is it just me, or does virtually every "Does she like me?" thread begin with "smiles at me" as a symptom and an attempt by the OP to convince themselves there's something more than friendship there?
As a result of reading so many times where "smiles at me" ends up being misconstrued, I've actually never ever assumed a girl was smiling at me; I've always chalked it up to "Oh, maybe she thought of something funny and just coincidentally is looking in my direction (which is very awkward for both of us)" or "It's not me that's causing her to smile; maybe she's drunk or hyper or high." Incidentally, I've never believed a girl was checking me out (which they very well shouldn't be: I'd question the sanity or sobriety of any girl that was).
I can now see why girls can be very distant: guys get too pompous and assume they like them after one small little detail.