i would recommed the altec lansing mx5021 system due to the way it looks similar to my axiom m22ti computer speakers... hehehe...
no, seriously though, the main thing that pc speakers lack is midrange reproduction (lets not talk transparency and soundstage here, this is a whole 'nother inadequacy).... the reason why these altecs are heads and shoulders above any other 2.1 system out there, is because due to its dual 3" woofers, it can reproduce mids far beyond the z680s that your friend has or the klipsch promedia 2.1s.
http://www.circuitcity.com/detail.js...&oid=80156&m=0
they might cost a penny over 100$ though, but imo, they are worth it if u want to go the pc route...
if it were up to me, do what i did, and get a real system hooked up to your pc.