In my travels, I have encountered many other sites that I often frequent. This is just a small sample of them for your enjoyment.
Cybernations.net - I started playing this game in the summer of 2006, and I really enjoy the challenges I encounter while attempting to operate a nation.
Star Trek.com - While the site hasn't been updated since CBS decided that websites for their "inactive" properties was not important, it is still a great resource for canonical information regarding the franchise.
Lunarwars.net - A game similar to Cybernations, but different, as you must operate as basically an independent piece of the moon, with no trading among colonies and operating with the limited resources you can find on the moon.