For less than $100 Roxio's diminutive Game Capture kit lets you play in high-def while capturing video of your Playstation 3 or Xbox 360 gaming sessions.
Introduced today, the external Game Capture device is about the size of a Nintendo DS and includes a set of component output cables and single USB cable to connect the device to your PC. (Mac isn't supported.) The kit also includes Game Capture software.
I've played around a bit with the tiny device and found it very easy to set up. The only draw back is the 480p cap on video quality, but for most users that's probably going to be fine. Kotaku uses Hauppauge's HD PVR system, which allows us to capture at up to 1080i, but also costs twice as much at $199.00.
While the Hauppauge kit is a must for laptop users if you have to capture at that high a quality, I found Roxio's software to be much more feature heavy, letting me capture in AVI, WMV, DIVX and export to H.264. You can also grab screen shots, saving as JPG, PNG, TIFF, BMP or GIF file types. The Game Capture kit also includes fairly robust video editing software.
For $99, it seems like a fairly good option for game capture, if you don't mind that 480p cap. You can see a short Rango gameplay session I captured above.