Previously available as part of Google Earth, Google has just launched a web-based version of Google Sky which allows you to explore the universe from the comfort of your own home. More information about this product is available from TechCrunch.
In semi-related news, Google gained the most advertising dollars of any media company – new or traditional such as TV/radio/print/etc. – in the last year and by a long shot…which is why they can put so much money into projects like this that aren't immediately seen as potential profit centres.
(via Reddit)