Its really really cool. You just type in what App you are looking for and it brings it up.
ALT+Spacebar brings it up
The are many free application launchers. Commonly these employ a dockable toolbar containing shortcuts to various programs on the PC. The toolbar can usually be hidden so it doesn't take up desktop space. I've never been keen on these things as often they achieve little more than what's available from the Windows Start menu. However, I've found an application launcher that actually really works. Launchy is a free Open Source utility that solves the fundamental weakness shared by many application launchers; intrusiveness. Unlike other products that use launch bars or tray icons, Launchy is invisible until you hit a special hotkey combination. By default this is Alt-Space. Hitting the hot key combination brings up a small window into which you type the name of the application you are looking for. You rarely even have to type the full name; mostly all you need do is just type a couple of letters. Launchy instantly displays on a find-as-you-type basis, any program that matches the letters you typed in. By default Launchy only searches files in your Start Menu folders. You can however, configure it to handle any file types and search any folders. So Launchy could be used to launch web link shortcuts or even your MP3 files. Configuration is easy; just right click on the Launchy Window. A top product.