The A5's include several input options for hooking up audio sources. There are two 1/8" stereo inputs (one on top, the other in back) for hooking up to your mp3 player, computer, or any other stereo source. Unique features include a USB charger on top for your mp3 player and second AC input for powering other devices including an Airport Express iTunes streamer.
Audioengine A5 powered speakers are much higher quality than typically found in stereo computer speakers or iPod docking stations, and because of this are more expensive coming in at $350. However, since you don't require an amplifier, these speakers can provide a great audiophile experience on a budget.
Consider a cheaper alternative in the M-AUDIO StudioPro 3 ($100) or their little brother, the Audioengine A2 ($199).