GSB for short or Google Search Box for long is a neat little tool from Google for the Mac. Essentially it is google search right on your computer. The neat thing about it is the speed and simplicity of it. Simply download and install, set up a quick shortcut and you are away.
Because it is Google and free they already have people writing plugins for it. So with the plugins you can set up your Google account and also your Delicious account. A little disclaimer, it is still in beta, however I have had no issues with it for just under a week.
Full details can be found here on the Google Mac Blog.