Which social networking site will work for me?

I often go on mission trips that require us to collect medical supplies or school supplies or things like that. I think it would be a good idea to use a networking site so that I could cast a wider net to reach people who may be interested in helping, or even going on trips.

I have little to no experiece with MySpace (although the pages I have seen seem awfully gaudy and “busy”), and I have never been on Facebook.

What are your opinions of these, or other, networking sites that may work for me?

PEACE!