hell, if you have her screen name, just send her an email and say you got it from whatever friend it was she mentioned in your conversation, and say you didn't get a chance to ask for her number, give her yours and if she's interested she will call.
ONLY send one email.....don't be a stalker, just say you are interested and leave it at that.
i was in a car wreck once, and was taken by ambulance to the hospital. one of the guys from the ambulance looked up where i worked and stopped by to say hi and he wanted to make sure i was ok. we dated for a year or so. he was and still is a nice guy. we would never have went out if he hadn't taken steps to look me up.