Is this a scam on facebook?

[John D]

Some girl added me on facebook who I didn't recognize but we had mutual friends so I accepted so I could see her profile to figure out if I knew her. Anyway, she joined facebook a month ago, only has like 30 friends, but 2 are mutual friends of mine and her other friends are also friends with the 2 guys I am mutual friends with. She only has one photo too (and it is not like a modeling shot or something that would tip you off its fake). I forgot I added her and never removed her after I realized I didn't know her. (that was like a week ago)

Today I get the following messages from her when I was on

Hey whats up?
Do u like to party?
I need to sign off right now, what's your cell number? i'll jus txt you in a bit

So what does that mean? Is she like a prostitute or a drug dealer or something, asking if I like to party and asking for my phone number? Or is this some sort of scam where they are going to do something with my cell phone # if I gave it them? Im not giving her my number, but I am just curious what is going on.