From Ajax Patterns

Stub pattern

Contents 1 Problem 2 Solution 3 Alternatives 3.1 Sound

Problem

How can you get the user's attention while they are working in another window.

Solution

Change the favicon dynamically, and possibly the page title as well. See this blog post, the demo, and the Digg conversation.

Alternatives

Sound

37Signals' Campfirenow chat app pumps out a Flash-based "earcon" (quick sound) each time a new message appears. This has alll the advantages and disadvantages associated with the audio medium; it will be a good cue if the user is performing typical work or moving around, but a bad cue if the user is listening to something else or has turned volume down, e.g. in a meeting.