The problems I've seen in several items that I've examined locally are that they tend to be "fragile" and lacking in quality. I guess the ole' you get what you pay for applies?
Retailers & manufacturers are trying to catch the coat tail ride of the IPod/.mp3 player market. Tremendous market for a quality item. I wonder how many of those inexpesive creations will be garbage in a few months, if not weeks? I guess there are some nice portable speakers out there for .mp3 players (who likes what? Any suggestions?)...but a set of amplified computer speakers work pretty good. As far as speakers in my coat, car seat, hat, etc...I'll pass.