Amazon offers its Amazon Prime members the Altec Lansing Orbit Portable MP3 Speaker, model no. IM227, for $13.11 with free shipping. (Non-members can get free shipping on orders of $25 or more; otherwise shipping adds $5.58.) That's the lowest total price we could find by $12. This speaker is compatible with MP3 players (including the iPod), CD players, and laptops. It offers up to 24 hours of play on three AAA batteries (not included).

Amazon Prime membership is $79 per year; however, Prime is free for college students for six months, and free for parents and caregivers for three months.