On Vista, you can also create a Task in Task Scheduler to send an email when an specific event is logged.
Windows Vista enhancements and new features
Windows Vista is able to schedule jobs to run at specified times more predictably, reliably, and securely. But the Windows Vista Task Scheduler goes beyond simply scheduling the tasks; new features in Task Scheduler also fulfill the need for more complex and proactive system and application management, especially task synchronization and activation on event. The Windows Vista Task Scheduler provides a platform for easy, secure ad-hoc management of client machines.
New Triggers. The ability to trigger a task based on any event captured in the event log is one of the most powerful new features of the Windows Vista Task Scheduler. This new capability allows administrators to send an e-mail or launch a program automatically when a given event occurs. And it can be used to automatically notify a support professional when a critical event—for example, a potential hard drive failure—occurs on a client machine. It also enables more complex scenarios, such as chasing down an intermittent problem that tends to manifest overnight. Task Scheduler can be configured to notify an administrator by e-mail that a problem has occurred. An administrator can also use Task Scheduler to automatically launch a program to collect more data when the error occurs.