Head-on shots are OK, but they get old after a while for me. One challenge is that it's hard to get a sense of speed and a sharp image of the car with the same shutter setting. I try to set it so that you can see a little motion blur on the wheels with a minimum of blur on the driver's helmet (or windshield, for closed race cars). Somewhere around 1/500th should be a good starting point.
It's easier to get a sense of speed by panning with the car on a straightaway. A slowish shutter speed (say, 1/125th to 1/250th) can give good results, with the background and the wheels blurred but the driver and cockpit sharp.
I never use a tripod at the races, and only use a monopod with very large lenses which are impractical to hand-hold (e.g. 300 f/2.8).
I'll be interested to hear if the Sony's shutter lag is usable for racing. I have not had good results to date with digital P&S cameras. I got spoiled long ago with film SLRs, so I have moved on to a Canon EOS 10D and 20D for race photography.
If you're creative, you can use the camera's limitations to artistic advantage. E.g. you might try getting some "atmospheric" shots where the track is stationary and the race cars are blurs against it. The Sony ought to be great for hand-held paddock shots; get a paddock pass and roam around between races. Don't be afraid to squat down, hold the camera at ankle level or above your head, etc., if it helps get the shot.
A manual-focus slide shooter lost in the world of digicams.