Theirs a girl I sort of have feelings for, friend of mine but she told a previous guy who asked her out she isn't interested in dating but me and her seem to get along really well.
Not going to ask anything serious, but would she find it weird if I phoned her out of the blue for a chat? Haven't seen her for a couple of days due to the fact I'm on study leave.
It would be a little weird depending on your relationship.
If you guys are more than acquaitances, then go for it. If not, it seems a little creepy. Try IMing her instead or find something in common to talk about ie. if you have the same classes, what was the HW or if you guys have a friend in common talk about them (but not out of the blue and not spitefully) and let the conversation go from there.
In case you haven't, it'd be ok to e-mail or call or whatever to get her facebook/myspace/IM/whatever so you'd have someone to casually talk to, but I wouldn't recommend calling her unless you have to. If you already have her IM or facebook, start talking to her there. (You can ask for her IM if you have her FB. I don't think that's a breach.)