Free.

Probably available this month.

Made Robert Scoble cry.

WorldWide Telescope, created with Microsoft's high-performance Visual Experience Engine™, enables seamless panning and zooming across the night sky blending terabytes of images, data, and stories from multiple sources over the Internet into a media-rich, immersive experience.

Official WorldWide Telescope site: 

you can zoom in and zoom and zoom and zoom...

It stitches together views from all the best telescopes in the world...

It's "like a magic carpet ride".

Technology rocks.  We are living in the age of miracles.