If you wish you could travel to distant galaxies and bend the planets you find to your god-like will, Galaxiki.org is the site for you.
Billed as a fictional galaxy that anyone can edit, Galaxiki uses wiki technology to present a sprawling galaxy of over 1 million computer-generated stars, along with their planets, moons and other orbital objects. Membership is free and gives you authority to edit community stars and objects. For a $12 fee, users can purchase a star and gain exclusive naming rights for it and its attending celestial bodies.
Launched as a beta in March of '07, Galaxiki has made significant progress and was chosen as Yahoo's Pick of the Day on August 27, About.com's Best Web Sites of August 2007 and Linux Journal's Community website of the week in mid-July. Upcoming additions to the platform include improvements to the physics properties of the solar systems, double star systems and internal mail for convenient user-to-user communication.
With just over 500 users as of July 2007, there are plenty more star systems waiting to be discovered. You can sign up for a free account and start making a contribution at Galaxiki.org.