YubNub is a command-line for the web. After setting it up on your browser, you simply type "gim porsche 911" to do a Google Image Search for pictures of Porsche 911 sports cars. Type "random 49" to return random numbers between 1 and 49, courtesy of random.org. And best of all, you can make a new command by giving YubNub an appropriate URL.
Bookmarklet Source Code:
javascript%3AQr%3Dprompt%28%27Search%2520YubNub%2520for%27%2C%27%27%29%3Bif%28Qr%29location.href%3D%27http%3A//www.yubnub.org/parser/parse%3Fcommand%3D%27+escape%28Qr%29
