Microsoft Gives You The Sky With WorldWide Telescope

First of all, if you want to try this baby for yourself, go get it here; the installation might take a while because you need .NET Framework 2.0 SDKs and DirectX (which I didn't have on my office computer). And if you can't remember what the hell WorldWide Telescope is, just remember that it was the thing that made Scoble cry. And we love things that make Scoble cry.

On a more serious note, it's Microsoft's latest desktop application which brings you imagery from many ground and space telescopes all over the world (and above it). It lets you explore space through guided tours, or freely, using a zoom-and-pan intereface.