If you sign up on Infosprite ( http://www.infosprite.com/
) you can get 20MB space to store Quake and Doom maps for free. The servers are pretty damn fast too, so it'll be easy downloads for others. Also, you can put your maps up on pages where you can give a small screenshot and a few details about the map. Also pcgamemods.com ( http://pcgamemods.com/
) offers you the latter, but not the former, so I only use it to put final maps on display. But you can put betas up and update them as you create new versions, but Infosprite's 20MB personal space for the files is more convenient in my eyes.