On my laptop I felt lucky to get double figures, with all the awesome turned down, and on the lowest res. If you're grumbling about 50-60fps... sheesh, gamers these days. Most LCD monitors run about that speed anyway: 60-75fps. So you're never going to get much better, because your monitor simply can't *display* better.
If it's a huge deal for you, though: crank down the quality of the graphics you're displaying. Turn off HDR, FSAA, etc.
If you want full quality AND crazy frame rates, then run some bench tests to find where your bottleneck is, then try upgrading that part of your system.
Also, try frobbing the "maximum pre-rendered frames" and other settings in the "3d settings" part of your nVidia properties. If you don't have an nVidia card, then consider upgrading to one: they have the hardware PhysX which might improve things for you.