jQuery Idle Timeout
See the original Mint.com example, or a demo using jQuery UI's dialog widget.
This script allows you to detect when a user becomes idle (detection provided by Paul Irish's idletimer plugin) and notify the user his/her session is about to expire. Similar to the technique seen on Mint.com. Polling requests are automatically sent to the server at a configurable interval, maintaining the users session while s/he is using your application for long periods of time.
