There are a number of amazing gigapixel inauguration images kicking around the web, but this one is by far our favourite -- because it lets you tag anyone you recognise via Facebook.
Put online by the Washington Post, you can pan and zoom to your heart's content until you find your nearest and dearest. Then, you can use Facebook to tag 'em. Clearly, as the Post points out, the tags aren't verified -- that would take aaaages -- but it's a fun idea nonetheless.
Depending on which part of the image you focus on, scanning the pixels is like a who's who of politics, the media... or an anonymous-looking crowd. [Washington Post]