An MP3 player is mostly a personal music device, but it also provides a great way to share music with others or even--in a pinch--satisfy your home stereo needs. To satisfy both the personal- and public-listening experiences, logic dictates you need two separate gadgets: a pair of headphones and a set of speakers. Or you could pick up GoStereo's Tune In Tune Out Headphones, which combine the two into one handy, simple device.
The headphones sound about average and the speaker quality is only so-so, but the superfair price of $50 for a 2-in-1 product makes the whole concept easy to swallow.