Here are a few of my favorite Windows Sidebar Gadgets.

1. isAlive

• Checks every 10 minutes to see if your website is up
• mirror

2. Piano (no longer avaiable)

• A small (or large, if you drag it off the sidebar) piano that you can play by clicking the keys or using your keyboard.
• Still beta, abandoned.
• download

3. Network Meter (download: wired/wireless)

• Although sometimes buggy, this gadget allows you to see all of the traffic going in and out of your computer’s NIC.
• mirror: wired/wireless

4. Skype Gadget by Craig

• Gadget that allows you to see who’s online.
• mirror

5. Amnesty

• This is a cool generator that lets you make your own gadgets out of web widgets from your website of choice. Its pretty cool.