Well, it seems like Mark Shuttleworth and his team at Canonical took a shot at it and hit the Apple straight in the seeds!
For those of us less familiar with OS X, Spotlight enables you to quickly access files or applications. Just start typing a keyword and your app or file’s name will show up as an option that you can select to access, much like Google’s Instant Search or the Windows Start Menu Search.
… And then there is HUD.
In Ubuntu 12.04 (Precise Pangolin), HUD takes the Spotlight premise and extends it to your current context.
You’re in a browser? Type a URL in HUD and there goes your browser making good on fetching your website! Search help, history, option menus. It’s ALL in HUD!
In an Image Editor? Same principle. Apply filters, resize, add layers, change colors all from the HUD. HUD is like the best friend you’ve never had, always listening and ready to help, no matter what the context!
Now, Ubuntu users can swear by the HUD! More about it in this video: