YubNub is a command line interface for the Web that allows you to start all kinds of Web queries by typing a command, e.g. "g" for Google, followed by the parameter of your choice. Typing "g c# UML" (without the quotation marks), for example, will yield a Google search for the search term c# UML.
Other popular commands include "wp" for Wikipedia, "gnews" for Google News, "tec" for technorati and "weather" (followed by a ZIP code) for weather information from The Weather Channel. In the same way you can use hundreds of other commands that have been created by YubNub's user community. Yahoo has a similar feature called Yahoo Shortcuts and Google lets you do searches like 10+5 or $ 10 euro, but none of these offers you nearly as many different commands as YubNub.
Somehow I like the idea. Since I stumbled upon the site a few months ago, I've been visiting it every now and then. I didn't really "adopt" it yet though. Maybe many others feel similar. Are we spoilt by GUIs so that we don't want to remember any of those commands? Or is Google simply too good, not leaving any space for a service like this? I think the latter is a problem for many startups which try to do anything related to helping people find information on the Web. Google works so awfully well, it's hard to make people remember an additional URL. If you search any kind of information, chances are you'll find it quickly by starting your search at Google.
As Google quickly turned from David to Goliath and I always sympathize with the Davids, I still keep my fingers crossed for YubNub, of course.