Another cool tool I found is
Gtray which sits in your system tray, checks gmail on a custom set interval, then pops up a balloon message in the tray if you have new mail. Works with IE, and the author offers no support. On my XP laptop it works well, but I don't get the balloon announcement. Still a much easier way to check my gmail by simply double clicking the tray icon and it opens IE, logs in gmail, and viola.
ed. Well, today the balloon's working, so who knows. Be aware that when it checks for gmail, you'll lose window focus, thus interupting what you're doing elsewhere while it works, but you can also turn off auto check and just use the tray icon as an easy double-click way to autologin and quickly check gmail. Still cool, and the author may improve it over time.