I prefer the 2m40s bit, where it is very responsive for such an old phone!
http://www.edbpriser.dk/Articles/Article.aspx?aid={28A2E156-F37B-428F-946E-36181E8AAA71}
(See vid)
It has some interesting applications, but their menu navigation ideas were ludicrous.
I use my hero one handed (or two handed to type messages) just about everything they showed would significantly slow down the use of the phone. Air Sig was ok. Turning over the phone when ringing already silences the phone by default. Touch-Anywhere sounds like it has plenty of applications too, but I don't know how accurate that would be, and it can probably be done via the microphone anyway.
It has uses for gestures (to supplement touch), games and adding faster mechanisms to do things.
I could see putting the phone down on the table automatically switching on speaker phone (more sensitive way of knowing it's stationary, combined with a few other fail safes would make this usable, whereas now it probably isn't). Faster response than an accelerometer is always nice for rotation etc. Wake the phone up responsively with a shake.
Other than that it seems a shame to try and force an interface out of the premise of not smudging your screen. It's a nice supplementary technology, but certainly not a standalone.