Although there are many iPod cases on the market that protect against dents, drops, and other such damage, I've heard from more than a few iPod users -- and know a few personally -- who simply want a thin pouch. These people generally keep their iPod in a pocket, purse, or bag where it's unlikely to be dropped or otherwise victimized by serious impact; their main concern is that their iPod doesn't get scratched by keys, coins, and other objects likely to mar the player's shiny surface, and they don't want to have to use a bulky case to get such protection.
Unfortunately, there aren't many pouches on the market aimed specifically at the iPod, but the good news is that the ones that do exist are generally very good. We previously covered the form-fitting PodSleevz from RadTech; Moshi's miniPouch is another good option. Made of the company's own "Terahedron" fabric -- which feels a bit like a thin but tough layer of fleece -- the miniPouch protects your iPod mini's finish without adding much bulk. The fabric is soft enough to be used to polish your mini's screen and body, and is "splash-resistant" (the company's term) and anti-static. A pocket on the outside of the pouch holds your earbuds, and a sturdy drawstring lets you close the pouch so your iPod mini doesn't fall out.
If you're looking for a thin layer of scratch protection that lets you operate your iPod in the case, we still recommend RadTech's PodSleevz; but if you're really just looking for a pouch, the Moshi miniPouch is the best option I've yet seen.--Dan Frakes