Newer Nokia phones like Nokia N82 and N95, have a built-in accelerometer and are capable of tracking your physical movements.
If you have one of these phones, you can download and install the Nokia Activity Monitor to measure your energy expenditure while you're walking or jogging/running.
This morning, as I checked out from my hotel and made my way to the Syndey airport, my phone told me that I walked 1,526 steps over a distance of 1.04 km, expending a total of 60 kCal (kilocalorie).
I may not exercise much, but according to my phone I'm getting quite a good workout every time I travel on business.
Signing off from Sydney airport...