Thanks to the GNOME Outreach Program for Women, I have just discovered Planeteria. It is a hosted service that makes it super easy to create a Planet (like the Fedora Planet). If you want to follow the progress of the changes to Planeteria by Aleta Dunne (the GNOME OPW intern working on it) her blog is the best place.
This service is awesome for the smaller open source projects that do not have the infrastructure to set up their own servers to host a Planet Planet or Venus instance.