I'm not sure whether it's a great example of Sitecore extensibilty or of things you shouldn't do, but I though I'd share it anyway :)

This little snippet adds shortcut to all content sections (and a little unsupported yet indispensable dbbrowser) to the Sitecore task bar. What is good about is, is that its very easy to install: download and unpack to your /sitecore/shell/override, its just two xml layouts with embedded code. The dark side is that you have to put them in override folder to replace the standard Sitecore start bar. So if the start bar changes in future builds - yours won't.

Fortunatelly, uninstalling is just as easy: remove the Startbar.xml and StartbarSections.xml files and thats it. Standard disclaimers apply: if your PC turns into evil alien monster and starts dissecting humans - you have been warned. Although it might be a good idea to keep your production server clean, I (humbly) find this control to be very useful in development environment.

Once again - download link (3kb).