I've never had a problem being "just friends" with a girl. I've been great friends with the girl I took to my Sr. Prom, even though the attempt at a "relationship" didn't work out. It was a little rocky for a while, but we got along great as friends and it wasn't terribly hard to maintain a platonic relationship. Honestly, I'm still attracted to her, but a "relationship" was tried and didn't work, that's more than enough to discourage furter attempts with that particular girl. There was no sense killing a perfectly good friendship though. Basically, it's quite possible and plesant so long as both parties are able to recognise and avoid self destructive situations such as repeatedly attempting a "relationship" that they intellectually know is doomed to fail. Mind over matter, if you don't mind the situation, it doesn't matter.
Zenmervolt