As many of you know IE9 offers a "site pinning" feature where you can drag any website to taskbar and "pin" it there. Site pinning is not just a shortcut. It's much more than that.
Hotmail now supports it fully. If you use hotmail/live mail, just login to your mail account, go to inbox and drag the tab to task bar using IE9 (on Windows 7).
Here's a screenshot from my desktop
Notice the hotmail icon in taskbar. It will notify me (without annyoing popup) of new mails and I can now access them with one click.