Riva Tuner is not just a tool to overclock your vid card, change fan speeds, tweek shader clocks etc. But I found out that it can also display different video card settings in game such as fps, core temps, mem temps fan speeds and all kind of stuff. It can even display cpu info with the right plug in.

Here is how to set it up.
http://www.overclock.net/nvidia/194389-how-use-rivatuner-screen-display.html

And download it from here.
http://downloads.guru3d.com/RivaTuner-v2.24-download-163.html

When I enable fraps (your rig may be different) it was using about 7-8 meg of memory during game play and Riva Tuner only used 1-2. Also with fraps there was about a 3% hit on cpu usage and none with Riva. Also with Riva you can display more than just fps.

Riva tuner will not record or take screen shots.  But it does a great job of displaying all the vid card settings including fps.  You can select what you want.

Bullitt