Getting phone numbers

[Protoclown]

Okay, so in the past three weeks I've been to two different parties (okay the first one was more of a small get-together at a friend's house but I still met quite a few cool people) and at both of these I met cute girls that I found very interesting/attractive.

For example, at the Halloween party last night, I talked to this gorgeous black woman (she had spikey hair and a Dead Kennedys t-shirt OMG *SWOON*) and I think she may have found me cute, because she kept looking at me from across the room. Eventually I went up and talked to her, she told me I looked familiar and she couldn't place where she'd seen me. So I asked her if she went to goth night (where me and Jaeger go to fag it up and play pool with the goths, he goes religiously every week, I go about twice a month on average), and she said she does once in a while. Then her friend (who I knew from years ago, but not very well) said that I look like this one guy they know up in DC. I asked if that was a good thing or a bad thing and they said it was a very good thing. Anyway, I talked with both of these girls for a while and the black girl seemed to think I was funny. Later on I noticed she was still looking over at me quite a bit, and once or twice she gave me a nice smile. So I'm pretty sure she was interested. Maybe it's because I was dressed like a Hawaiian monk, or maybe she thought I was cute, I don't know.

Anyway, eventually I had to leave the party and I didn't get a chance to talk to the girl again. I really wanted to get her phone number or something, but I just don't know how to ask someone I literally just met like 10 minutes ago on a date. I always kind of figured it was more appropriate to wait until the second time you see someone. So basically I just need to know what I should say or do in another situation like this. I THINK I'll see this girl again, because I know her friend, and evidently they are best friends. So if nothing else, the next time I see her friend, I can tell her I found this girl very attractive and I want to know if she's available. Or I may run into her at goth night.

Is it appropriate to ask for a phone number so quickly, and if so, how do you do it without sounding like a desperate doofus?