You already saw Google Chrome's humorous about:internets Easter egg, but reader nettleman points out that Chrome's got several special about:
pages that reveal all sorts of interesting information about what's going on behind the scenes. Here's the full list, with screenshots.
about:memory
about:stats
about:network
about:internets
about:histograms
about:dns
about:cache
about:crash
about:plugins
about:version
Update: Mawin adds that you can also go to two special pages on a per-site basis. view-cache:[URL]
shows you some under-the-hood cache details, and view-source:[URL]
shows you the page's markup. (Though you can view source by just right-clicking on a page and choosing, um, "View page source.") You Mac and Linux users, here are some about: page screenshots:
Find anything interesting in Chrome's about: pages? Let us know in the comments.