Custom label colors: If the 24 standard color choices aren't your thing, enable this feature to create your own custom color combinations. Instead of choosing one of the standard colors from the label drop-down menu, click "Add custom colors," pick your palette, hit "Apply," and enjoy.
Go to label keyboard shortcut: Never have to click on a label again. Instead, enable keyboard shortcuts and press "g" then "l" to display the "Go to label" pop-up. Start typing, and your labels will be filtered as you go. You can use the arrow keys to select a label and hit "Enter" to select one.
Powertip: The pop-up searches each word in your labels for a match, so if you have multiple labels with the same prefix, simply add a space, dash or slash after the prefix and search for the second word. For example, typing "labs" will display labels named "gmail labs," "gmail-labs," or "gmail/labs" but won't display "gmaillabs."
Navbar drag and drop: If Labels are more important to you than your Contacts, you can switch them around with this Labs feature, which allows you to reorder the items in Gmail's lefthand navigation bar using drag and drop.