Looking for software - forming groups

Hi, I have a question I'm hoping someone here can answer: I am looking to find a software package that form people into groups. Here's what I mean:

I want to have, say, 300 people enter some basic data, like an area of interest, maybe their zip code, and their level of expertise. Then want the software to form groups out of of that information, like groups of 3-5 people, and have either their emails all together, or maybe I'd create a separate topic in a forum board for each group. Is there any software out there that could something even vaguely like what I'm talking about? I know there are membership sites with 10,000 people in them and they have small groups set up, so it must be done by software and not manually. Any ideas for me? Thanks!