Gmail Hacks
Subject:   Chore?
Date:   2005-01-26 09:50:34
From:   pixelgeek
The Gmail Notifier resides in the System Tray and pops up a message whenever a new email arrives, saving you the chore of manually checking for new messages in the web browser.

Keep a browser window open and in Windows the title of the taskbar will tell you when there is new mail in your inbox

How difficult is that?