Wow, been there done that!!! The only guys I ever get a crush on are straight. Sure it sucks really bad, but the only thing to do is accept it and move on.
If you know the friend you have a crush on is straight, don't get your hopes up with that 'well he hugged me once, so maaaaybe there is a little chance he's gay' stuff. I know it feels so good to be around that person and wonder whatever could be, but in the end you are only hurting yourself.
What I try to do every time, is just to think. NOOO THIS GUY IS OFF LIMITS! NOT GONNA HAPPEN, BACK OFF!
The sooner I get that into my thick skull, the sooner I can distance myself emotionally from my crush, and then I feel sorry for myself because I'm still single.
But then one of my friends is always there to remind me that I have plenty of reasons to be happy. I'm healthy, my family's healthy, I have great friends who really know me, I'm enjoying college, and eventually the right man will come along, what's there not to be happy about?
Some straight guys are so damn cute! But then I always try to find some hotter gay guy, he always turns out to be an asshole, slut or taken, but I don't care, the more friends the better right? Friendships last longer then relationships anyway (most of the time that is lol)