I'm in love with the Creative Xmod. It's this little white box that hooks up to your computer by USB. And it turns your plain ordinary headphones into a virtual 5.1 surround sound system. I used it to watch my copy of Cars. I tell you, those race cars were racing around and through my head. That's how cool the virtual localization was.
The box works by creating virtual speakers that surround your ears. Yeah sure, your headphones only have two real speakers, but somehow the engineers at Creative have figured out how to localize sounds by using advanced digital signal processing that even takes the physics of your head and the shape of your ears into account. It wasn't exactly like being in a theater and really feeling the sound effects with your whole body, but it took the sound experience up to a whole new level of listening.
The XMod hooks right into your Mac via USB. It then grabs any audio playing through the system and runs it through its built-in filters. You hook up a pair of earphones or speakers to experience the effects. The virtual 3D surround sound works particularly well with both movie playback and gaming.