We have a cheesy body-fat scale. It seems accurate enough--the scale portion generally agrees with our doctor's scale, within about a pound or so. The body fat measuring part seems to be fairly stable, too. When I was checking on a regular basis it never fluctuated much at all from week-to-week.
I've made more progress in improving my body composition in 6 weeks of biking and weight-training (due to that pesky sprain that prevented me from running) than I did in 4+ years of running. Hmmm... It doesn't hurt that biking and weight-training don't cause my appetite to spin out of control, like running does (for me).
My actual weight has been pretty much stuck, but my clothes fit better and I have definition developing in my arms, quads, and abs. The weight doesn't really matter when I am displacing fat with muscle and seeing my "measurements" shrinking. Though I am prepared to have to do some intensive jean shopping come Fall. My waist continues to shrink as my rear and quads maintain size. I have heard that Lucky brand jeans fit "athletic" women well (I've been told this from weight-lifters and cyclists with bulkier quads and narrow torsos).
So I'm thinking ahead to Fall and Winter training. I'm not sure how much running I will do. I do want to be relatively well-prepared to run the Las Vegas Half-Marathon in early Dec., but I'm not going for a PR (wouldn't be likely with that crowd and the training I have lost with the sprain, anyhow). At this point I think my time would be best used riding the "nowhere bike" (road bike on the trainer) and 3 days/week of upper-body weight training. With maybe 15-20 miles/week running--just enough to not have me lose all running fitness. I still want to do some Spring running races.