If you haven't seen NASA World Wind you've GOT to check it out.
It's program very much like Google's Keyhole but Keyhole costs $29 a year to use. NASA World Wind is free and in many ways has more features.
It's a 3D globe viewing program where you can zoom in to the under a meter range. Here's me zooming into the old Naughty Dog building on the 3rd Street Promenade in Santa Monica.
the west cost of North America
the greater Los Angeles Area
the Santa Monica Pier
The top of the old Naughty Dog offices.
Not only that but it NASA World Wind can display 3D. Here is Mount St. Helens from above
Mount St Helens
And here it is in 3D, just tilt the display with you mouse
Even more NASA World Wind can display data from 6 or 7 sources and on top of that it has a whole bunch of event and or special data. Here's one example. This is the trail that Lewis and Clark followed.
The Lewis and Clark Trail
All those points are linked to an actual website, Click point number 3 and up pops your browser with more info.
Another example, here is the sand displacement data from over the Sahara.
This particular data is animated showing the sand flowing over the globe. You can really see what's going on. They have hundreds of data sets. The majority of it is downloaded as you request it over the net so if you don't have a fast connection to the net it could be a while coming down. Fortunately it can cache the data so if you go visit the same place later it should come up quick.
It's been a while since I've been inspired by NASA but there's something extremely cool about World Wind. Sure it's probably not going to change the world but it seems a step closer to that utopian Disney like future I dreamed about as a kid.