I've just spent 30 minutes playing with Google Earth, and it has simply blown me away. Just an incredible mixture of search, maps, and satellite photos. Being able to chart a journey across a landscape with a 3D perspective is an amazing experience. Unfortunately, if you are on a Mac, you're shit out of luck for now, but if you have a PC, go download the free software now. Then go for a little sightseeing. Make sure you turn on the 3D terrain and Buildings.