The iStik is a carrying case for second- and third-generation iPod nanos. It costs $24.95 for second-gen and $26.95 for third-gen nanos respectively.
Rather than using a belt clip, strap or carabiner to stay in place, as many cases do, the iStik uses eight Neodymium magnets to secure the iPod. You can attach the iStik to any part of your clothing, similar to how a magnetic name badge works.