Growl On Your Phone
Visual Studio Add-In
Get notified of success or failure when builds complete.
Can be configured to send notifications per-project or only for the entire solution.
Works with VS 2005, 2008 & 2010
UPDATED 11.27.2009 - Fixes a bug that could cause the project name to be incorrect in the notification.
UPDATED 05.06.2010 - Now works with Visual Studio 2010.
UPDATED 08.27.2010 - Now registers separate notification types for solution succeeded, solution failed, project succeeded, and project failed so you can set individual options for each.
Growl for Windows
Visual Studio 2005, 2008, or 2010