Adding Surround Sound
Well, leave it to those crafty folks at Griffin Technology to solve the problem. Their FireWave product adds Dolby 5.1 surround to your Mac via the FireWire port. It also includes a FW port of it's own, so you can still add drives, cameras, etc. to the Mac. And it doesn't need to be plugged in to the wall, getting it's power from the FW port (as any good FW peripheral should).
Tack on another $99 for surround!