Yeah, you could use them for HT...but it'll take a visit to Radio Shack for an ass load of "stuff."
Just remember that the PM 5.1s interface with 3 1/8" miniplugs and not RCA (composite). You'll have to get a hold of adaptors that'll let you go from that 1/8" miniplug to composite (stereo). Now, you'll have to have a receiver that has RCA connects for your speakers which, in itself is a loss. Connect the adapted "front" speaker wire to your receiver's "front" RCA connectors. Connect the adapted "rear" speakers to the receiver's "surround" RCA connectors. Finally, connect your adapted "center" speaker wire to your receiver's center and subwoofer inputs.
With all these wires, you'll probably lose some--you'll also be losing on a lowly receiver...you could always buy that SoundBlaster Extigy.