Egoboo 2.6.1 (stable) is ready for consumption (go there for download links). Go kick some ego ass with this revived classic. For braver souls there's also the development version but the Linux effort lags a bit behind the Windows effort with that one.
There's also a great overview of the upcoming Scourge 0.20 release. The features for version 0.21 sound very promising. Scourge is very close to having enough features and contributors to make it a very, very nice game and if support for the Worldforge model format gets done, I can see some nice new models making it into the game and it finally getting some credit.
Here's pictures of Project Football, an exciting project to create a soccer management game. The site is mostly in Spanish though the author posted a thread in the FGD forum.
Finally, the author Stormbaan Coureur of has posted the following request for pledges towards a game he has been creating that fully simulates a tank with tracks. If he gets enough pledges, he'll make it open source, and it's certainly a very cool prospect. He's going for $1000 which, when you think about the megatons of money some rather rubbish commercial games make, is very little given how cool it is. How cool is it? Have a look at the video below. Here is the the pledge page.