I liked Google Desktop even before it added the sidebar. The ability to quickly and easily search your hard disk for files and emails is something that should be built into the operating system, but Windows’ built-in search function has been notoriously slow and quirky; Google Desktop does it a lot better. (Sorry, Microsoft.) Add the sidebar and all that marvelous gadget content, and you have a winning application—one that’s both useful and fun.

Trust me on this one: After you install Google Desktop, you’ll use the desktop search a lot, and you’ll constantly be trying out new sidebar gadgets. The desktop search is an invaluable tool, and the sidebar is just plain addictive. It’s something you’d pay for—except you don’t have to, because it’s free.