What is your budget? Most bookshelf speakers would indeed require an amp because they'd be configured for entertainment centers consisting of 2-6 or more speakers. There would be no way for you to connect them to your computer unless the speakers themselves featured auxiliary ports. Then you could hook them up to your computer or iphone's 3.5mm jack with a stereo aux cable. Some speakers have connections for headphones and mics on the actual box as opposed to patching through an amp or the computer itself. [url=http://s1.hubimg.com/u/2108472_f520.jpg]My speakers[/url]. They're great quality and I can take the aux cable out of my PC jack anytime if I want to play an mp3 player. If you don't want to purchase an amp you should stick to a pair of stereo computer speakers. Jacob also brings up a good point. If portability is an issue then a center station or travelling speaker would be ideal. Though what you gain in mobility you lose in quality. [Edited on 09.13.2012 12:38 AM PDT]