The Boom Bag is a nifty pre-production unit that combines all the fun of bags and bag carrying with iPods and iPod listening. A "full range" speaker is located on the inside of the bag, as is a rechargeable battery. An iPod is then hooked up to the speaker; music then plays from said speaker. The bag is made out of weatherproof fabric, so there's no need to worry about Old Man Winter ruining it.
The Boom Bag was borne out of a study looking into loud speakers, much like how microwaves were borne out of experimenting with radar waves.
The design firm, Gro, is currently looking for someone to help pay the bills so it can actually mass produce the Boom Bag. So if you're feeling generous, give 'em a call. Just be mindful of their flash-heavy Web site.