One of the first things that struck me about Animal Crossing: Wild World was the virtual surround sound. This can\'t be explained, you have to experience it in person, just playing with the console. Very intriguing.
Back in Sofia, and with access to the internet, I decided to research this a little. A couple of hours, and countless webpages later I am familiar with the concept of HRTF, I\'ve skimmed through at least two NDS homebrew development guides, and have discovered at least one nasty thing: Soundhack\'s demo Spectral Shapers have the nasty tendency to go mute as soon as they expire. This is silly. Tom Erbe, if you ever read this, please, you can\'t bend people\'s wrists this way...
Back to surround sound. Amazingly, the effect seems to work in small devices\' favour, so while it wouldn\'t work on my delicately spaced ESIs it does miracles as soon as I unplug the line out jack, and try the laptop\'s internal speakers. Very interesting.
Trond Lossius has nice summary about virtual surround software on his blog. Edit: Logic Studio now supports binaural panning (!). This is a really interesting topic and you owe it to yourself to explore it, if you have the time!