TwitterFaces is a hypnotic glimpse into the lives of people around the world. It's a complete waste of time, in the same way that conversation, casual s*x, and reading are wastes of time. It generates an amazing feeling of connection to what people are thinking of in the world .
This is a kind of ambient zeitgeist for the world and word of it is spreading like wildfire.

Twitter and Microsoft Virtual Earth mashup. See tweets mapped on top of a map of the earth.

See Tweets on a 3D globe of earth from space. Very cool!

See Twittervision on your desktop screensaver

Geo Twitter
The most recent updates are fetched from the public timeline and mapped once every minute.

Twitterami
Frappr and Twitter and a world map. All mashed up for you. Requires a user account.