If you already wear a badge on a lanyard at work, why not add a pedometer? I wear a cute handmade lanyard from Etsy with my badge and an Omron HJ-203 ($20 @ Amazon) "pocket" pedometer. I like not having to connect to my waist, and my dress shoes lack shoelaces, so the lanyard is the way to go. Plus it's cute, and it has a handy clock to boot!
I added a jump ring (very cheap, used for jewelry, see your local craft store) so the pedometer can be detached & worn in pockets on evenings, weekends. They come in pink (mine), yellow, purple, and black. When you make 10K steps, there's a little guy in there that cheers!