It was romantic comedy about girl and guy who know each other since collage time.In the beginning they didn't like each other (the guy was a bit nerdy),they met rarely, later get friends and in the end realized that are in love.

Might not be the right movie but maybe you're thinking of Just Friends?
http://www.youtube.com/watch?v=UnKSPJdpyWo&NR=1
Try this link for the trailer and see!