I won a Nano as part of a Christmas giveaway, and to be honest I wasn't expecting much. How could such a small device be any better than the speakers built into the phone? Seriously, this thing is TINY:
I was not prepared for how much sound it puts out. The bass is a bit lacking (obviously) and it's not going to over power a room full of dancers or anything, but it's a great fit for on-the-go audio when you need a quick boost of sound. Currently, I'm using it as the audio system for my truck, which has no stereo, and I couldn't be happier.
The only downside is the battery life. It clocks in at under 4 hours, but hey, it's tiny!
Anyway, it's very reasonably priced, durable metal case, and TINY! You can legitimately fit it in your pocket or the extra pocket of a back pack and have sound on the go whenever you need.