GPS Utility Fix

I read a while back in a Car and Driver, or some other magazine, that you are able to calculate your 1/4 mile time, and therfor estimate other car components via GPS.

Well, i got a GPS system now on my car, and i want to fully utilize it for that purpose, anyone have any ideas?

I asked this awhile back, and didn't ever get an answer. If you happen to find out, i'd like to know.