The Two Micron All sky Survey has mapped 500 million point sources in the universe. I've been poking around with the data. My initial attempt was to render it all in realtime. I soon learned a thing or two about the filtering and data processing involved preparing astronomical survey data. In the mean time I've published a WebGL-based visualizer of the 2MASS Redshift Survey data, containing only 50,000 points, albiet pre- filtered and processed points at that. This can be seen on my WebGL Universe page.
I'm still pursuing a realtime, web-based visualizer of the entire 2MASS dataset. While I have nothing realtime to show, I do have a method of producing still images.