Well I went out meet a girl we took a picture and I only have her first name stupid me never asked for her number thinkingI was going to see her aagain

Impossible.

I've heard of people finding their adoptive parents or long lost family members just by posting a picture on Facebook page. The chances are slim of finding her through this way and maybe you don't want to put her picture out there without her knowing, but there's no other way to find someone with just a picture if you don't put it out there.

Facebook is the way to go, but harder without a name. Not saying you should post her pic. Do you have any idea where she lives? Near you? FB does have ways of narrowing down finding people.

Why don't you share your story and forums and then express to them how you really want to see this girl again. The word might spread and eventually, her friend will hear about it. You should be very specific on the details. What place, date, etc.

Never used it myself, buy you may have some luck with TinEye (http://www.tineye.com/) or PicTriev (http://www.pictriev.com/)