I read about this gadget somewhere and decided that I wanted to try it. With shipping it's about $25, and it's called the Gym Boss. It's great for the interval exercise plan (or any interval plan, or stretching) in the new SB book.

You can set it up for as many intervals as you want and it can cycle between two different intervals. So, since I just started the plan, I set it up for 15 seconds, then 60 seconds, 6 times. It beeps after each interval and then at the end. That way, you don't have to keep looking at the clock.

It was great because yesterday, I didn't have time to get to the gym, so after dinner, I strapped on my heartrate monitor, put in some latin music, and danced with my boys (10 months and 3 years). (It's amazing how much more tired I felt when I was carrying 20, 30 or 50--when I was carrying both--extra pounds around!) Anyway, after about 10 minutes, I turned it on, and I knew when to amp up my effort. And I felt great having gotten my cardio in!

You can get it at www.gymboss.com.