There used to be a website that had about 700'000 invites to give away but Gmail's product manager made them stop the service. This is directly from the webmaster of mentioned site.
I have gotten the word from Gmail's Product Manager that my service is no longer tolerable. At midnight PDT June 7th, 2005, this service was disabled. I would like to extend my sincere thanks to all who contributed to this service. Your generosity helped out a vast number of people and for that you should be proud