I downloaded and gave Tremulous a shot tonight. It's based on the Quake III engine, which is now some 6 or 7 years old, and still pretty.
This laptop is pretty lame though, so I had my doubts. I checked on the original Quake III system requirements and was amazed at how weak they seem. I remember when the Quake III demo came out back at Fitten and Jeff gave it a shot on his brand-new Voodoo card. I didn't even have the horsepower to run it back then, but now even a laptop lacking a graphics card can render at 70-90 frames per second.
With that in mind, I might have to reinstall Star Trek Elite Force.