I'll second the M-Audio BX5a's.If all you neeed are 'Nearfield' monitors, these are plenty. They're individually AC-powered, and bi-amped -- 40W amp to the 5" woofer, 30W amp to the 1" dome tweeter, so the low and high ends get pure juice and the crossover network takes care of distributing the mids. They're loud enough to fill a living room with sound if you wanted to (I even used them with a laptop, boom box and vocal mic into one of the mixers in this photo here as a PA for a birthday party in a community center hall about 20" x 50'), but I employ them as otaypanky does, desktop (mine are 'isolated' by setting them on acoustic foam intended for that purpose), in a 10x10 room. Set them at about the height your ears will be, spread and angled inward like at your nose. Like this:
To get the signal into them from your computer, you'll probably need a stereo y-cable with a stereo mini-plug (1/8") out of your 'puter's audio out and 2 1/4" mono plugs to go into each of the BX5a's. You could get fancier if need be, with XLR plugs or balanced 1/4" plugs for lower signal noise, because they have both those inputs.
EDIT: -I hadn't looked at your link to the m-audios you were checking out; besides a bit smaller woofer/tweeters, those are simpler (not bi-amped, lower powered) and have RCA and 1/8" signal inputs, making them simpler to hook up with your computer than BX5a's. They're also about 1/2 the price (new).