Amazing isnt it?
HiDn, I guess You can track a trend using the BF scale although it may not be very 'accurate' .. lets say you weight yourself 3 times and the figures arent WAY off for scale weight & BF % ... you can take the average for the 3 and monitor that to see if there is a shifting trend in progress (although it's really a PITA way to track, but hey, I know people who've done it.)
You can order fat track gold (I think that's what it's called) online to get digital calipers if you want to make the purchase.