Basic Car Pool Site

I need a basic carpool/ridesharing coordination site made. Basically, my organization has people around the country, and we are planning a meeting. So, I need a website to coordinate ridesharing. Basically, anyone can enter in thier email address and zip code and then select from a few options like "i need a ride", "i have space", "looking for busmates" etc. There will be a big map of the usa which will have dots of certain colors to correspond with the submissions. The admin will have access to the database to help coordinate. People will be automatically emailed with corresponding matches. I think flash and actionscript with mysql will be prettiest, but i am up for suggestions. I will supply graphics and mock ups for the design, so this is mainly a programming job, not much visual design needed.