As Google takes its privacy-exploding eponymous Desktop Search app out of beta, it seems to have picked up an idea or two from Nicholas Jitkoff’s classic world-bending launcher, Quicksilver:
Three months ago, I came up with an idea that makes it easier for users to find what they’re looking for: a search box in the middle of the desktop. It’s very accessible — all you have to do is press your Ctrl key twice. After some experimentation, people are telling us they like it and use it.
Factory Joe 
Quicksilver-eske but also very Spotlight. If you haven’t tuned into Spotlights plugins recently their is an awesome one for del.icio.us.