Keyboardr is a nice mashup with Google search results including images, blog posts, Wikipedia and YouTube results. This web app is super fast and displays search results as you type.
Keyboardr has support for keyborad shortcuts, it displays the results as you type and you can use navigation arrows to select the results and hit enter to open the selected result. Not only YouTube, Google and Wikipedia it has plans to introduce more services soon.
Search results are organized in columns with left column containing Google search, Google blog search and right column with Wikipedia, YouTube and Google Images (something like Yahoo Glue). It displays a All Results clicking on this will open normal results from any section in new window.
If you are a keyboard ninja sure to check this app, the more exciting feature of this app is how fast it displays the results.