The latest iPod Nano includes a pedometer application by default, which is something I thought about some time ago. An advanced pedometer with a calendar and clock can relieve you of the need to write down your step counts or reset the device daily. It makes more sense that way from an ease of use point of view, but I won't get an iPod Nano just for that. The problem is having to carry it everywhere and leave it on all the time. The only thing I do that with is my phone, which kind of makes the point for buying a smarter phone, not an iPod.
Mokalus of Borg
PS - For now, my regular old pedometer does just fine.
PPS - And I expect it will continue to do so.