iStik is a brilliant but simple product that allows you to fasten your iPod Nano to any article of clothing anywhere. Fit the case to your iPod, place on one side of your clothing and the magnetic clip on the other, and presto you iPod will look like it’s magically stuck to your body. The iStik uses Neodymium magnets which should insure a tight fit.
Available here for 2nd and 3rd gen iPod Nanos starting at $20
One more pic after the ‘leap’ of some chick with a Nano on her butt