You can take the party with you, if you're willing to lug around the Ion iPa03 PA system which docks an iPod, and comes equipped with a microphone so you can protest 'seal clubbing' on any street corner. Surprisingly, the system runs on rechargeable batteries which last over six hours. The system conveniently, has a retractable handle and wheels, so you can also roll it to your neighbor's house if his next Halloween party needs a little music.
"Broadcast your iPod anywhere, anytime with the professional line level output and high sound fidelity. Compatible with all iPods with universal docking connector. The iPA03 is perfect for music on the go. You'll find it at seminars, fitness instruction facilities, outdoor musical and sporting events and even in a one-man band." Via Ministry of Tech