"Gesture Search from Google Labs lets you search your Android-powered device by drawing alphabet gestures on the touch screen. It allows you to quickly find a contact, a bookmark, an application, or a music track from hundreds or thousands of items, all in one place. It is fast and fun to use."
In the screenshot below, you can see Gesture Search in action: after drawing letter "a" in the Contacts app, the user draws the letter "n" to quickly find Andy.
Gesture Search shows two important things about Google's mobile operating system. If you use an Android phone, you'll be able to try a lot of great apps developed by Google. Another important thing is that Android apps can integrate with built-in applications, so you're able to find applications, contacts, songs and bookmarks using a third-party app.
Unfortunately, Gesture Search is only available for Android 2.0 and not many people can upgrade to this version without buying a Droid or a Nexus One. At least for now.