Google Earth
I'm completely fascinated by three-dimensional mapping technologies. If you combine 3D mapping with something useful, like locating a place to eat or where to buy cheap gas I'm even more impressed. Google Earth brings an amazing 3D look at the planet with an impressive drilldown with satellite data that offers top down views of landmarks like the Egyptian pyramids coupled with more useful information like searching for "family friendly restaurant" and getting accurate results for restaurants which are capable of handling everything from couples to the 2.3 kids and grandma in tow. Driving directions and map routing round out the package, getting yourself to there and back again across town or around the globe. The free version of Google Earth is screen resolution imagery, with a $20 plus version offering reasonably effective printable versions of the same maps. [Windows 2k/XP $0.00]