I just install Synapse, which is very similar to the Quicksilver app on the Mac. Control+Space and you can type the name of the application that you wish to launch.
Better auto-completion (I can type ref and it'll find Firefox and anything else that matches). Better file finding (I can take a screenshot and type 'scr' to find my screenshot instantly). Imgur uploading (I can find my screenshot, tab, down, enter to upload to imgur, copies url into my clipboard). Hooks into media players. Hooks into OS (can logout, suspend, shutdown). Better UX, left/right/up/down/tab are all binded to something useful. Faster. Can run on stuff besides Unity.
