You guys should check it out, its a very well designed game, and It was in development for nearly 5 years! I'ts browser based, but with a slim downloadable client.
I played it during the beta (was known as Space Civilizations at the time) and I thoughtit was pretty sweet. Its basically turn-based, but at set time intervals. (one hour for normal galaxies, 30 mins or less per turn for speed galaxies) and its one of those "easy to learn, difficult to master" games in that its elegant in its design, but very deep in possible strategies.
Oh, and by the way, it can be played free forever, but if you ever decide to get a premium membership, its rediculously low per month. only about $2.25 a month if you buy a year membership!!
Seriously, give it a try.