Aperio has a partnership with a company called Zoomify, which makes web-based image viewing tools. We recently collaborated on a Flash viewer for virtual slides. Zoomify provides the front-end client, and Aperio provides the back-end server (as well as having digitized the slides with our ScanScope scanner). The results are amazing.
Below are some actual virtual slides; click on any of the thumbnails to launch the viewer. Now you, too, can be a web-based Pathologist!
Note that several of these images are larger than 10GB! Okay, I know I'm bragging a little, please forgive me. I just thought it was cool :)