Auburn is a free desktop tool which allows viewing your current AdSense earnings, and notifies you when new money arrives.
Sign in to AdSense and Auburn displays your current earnings balance in a system tray icon.
Receive new earnings and you're informed with a tooltip and audio alert.
Options include the ability to display AdSense earnings for the past 28 days, rather than your balance.
You can also change the check interval to anything from 30 seconds to 120 minutes, set a new tooltip duration or use a custom audio alert.
Version: 1.09 · New: Google AdSense updated for new website layout
Most people probably aren't earning enough from AdSense to need regular updates, but if you're one of the lucky ones, Auburn will keep you in touch with your latest balance.