Nice, thanks for the heads up!
I've pretty much given up on multiseating by now - have got a new PC since then.
But I'm always intrigued by the concept of it.  New version supports both 32 and 64 bit flavours of Windows 7 it appears, so I might give it a try when I get some time.
Heh, could always be a quick backup solution should I want to multiplayer something when someone comes over.  Have two monitors (though only one plugged in at the moment) and a sound card + integrated audio.  If SoftXpand can separate the audio to different devices, setting up a second "machine" would be just a matter of plugging in a separate keyboard/mouse and headphones and redirecting video across.

Thanks for the offer too Yairf!