I've got a fitbug and it works clipped anywhere: waist, bra, pocket, shoulderbag while out, even clipped to your sock or trainer. It came with a neck thing to hang it on too, but I've not used that cos I wear 2 necklaces and am scared of getting them tangled. It costs more than the other omron ones, but uploads to the website and you can input food intake for calorie/fat/carb/protein counts too. Plus back-up from their experts and insurance so they just replace your fitbug if it breaks or gets lost. It's cheaper than WW or SW anyway.
The other omron ones are good too, but won't upload.
Hope you find you what you want?