So last night was a productive one for me, two girls gave me their numbers and both said to call them to hang out. However, I will be out of town for next couple weeks, so I am trying to figure out the best way to approach this. Would texting right now to say "this is so so and so, it was good to meet you" be a good approach, and calling her later when I am actually back in town? Or, is it better to wait to start contact until I will be back in town?

Start contact when you arrive back in town. It will be even more of a surpirse to them.

Tick

I would recommend telling them that your going to be out of time for a few weeks, but that you would love to catch up afterwards...

So they don't loose interest.. (because they haven't heard from you in a while)

I'm with ken (had to spread rep).

Better to get in contact now and to let them know that you're out of town so that there's on misunderstanding or confusion when you don't contact them while you're away.

You don't want to start on the wrong foot.