Haha I love that feature. Its saved my arse a couple times when I've gone offroading and there is no track to follow!
Crazy technology these days.
AMS's super advanced Chinese eclipse DVD unit in the STi drops little blue dots on the screen everywhere you've been.
So you can find your way back home.
Audi's have a really neat feature with their new internet enabled head units - the POI's are linked to the Google business database so you can see a street view image of the location you want to go to + see a description of that business.
All this stuff is unnecessary but can't help but be impressed by it all.