But coming May 26, you can hook one up to your Nintendo DS or DSi handheld gaming system. Personal Trainer: Walking ($49.99) is a DS program that comes with two Activity Meters — battery-powered, sleek, beach-pebble shaped monitors that you can clip onto your belt or just slip into a pocket or purse. You get a black one and a white one, and extra Activity Meters can be purchased so up to four family members can use the program — even the family pet (clip it on Fido’s collar).

Here’s where the fun comes in. When you set up the program on your DS you can either create a Mii character or import one from your Nintendo Wii system. The DS-created Miis are nearly as variable as the ones on your Wii — you can diddle with hairstyle, facial features, even your track suit. And yes, you can create a Mii for your pet.

The Activity Meter “talks” to the DS program with the press of a button on the meter and it sends your activity information to the program, where it tracks your activity through the course of the day, so you really only need to wrestle the DS away from your kid once a day. If your steps exceed your daily target, the light on the Activity Meter will change from red to green. Once the data has been transferred, you can see the results on your Nintendo DS system.

The program can store 5 years of activity info on up to four family members, and it also dispenses healthy-living tips, so it’s nearly like having a personal trainer at half the cost of a session — and that’s for two people. Check out the video below (don’t worry that it’s in Japanese; it shows how the program works):