The one thing OS X doesn't lack are app launchers. Spotlight is built in, of course, but there are a wealth of third party options: Alfred, LaunchBar, QuickSilver, and more.
I've been using Alfred for awhile now, and much like the other apps I listed it does far more than merely launch apps. Despite the power under the surface, the only thing I use it for is... launching apps.
Chuck is a new (to me at least) app launcher that only launches apps. No fancy workflows here, no way to open 18 apps at once and edit a file while calculating Brazil's GDP with a single keystroke. Nope, you bring up Chuck's interface with an assignable key combination, type, and launch your app. Plus, Chuck's icon is a mustache. Awesome.
Chuck's interface is pretty simple:
Start typing and you see this:
Hit Enter and your app (in this case Skitch) is launched and Chuck's interface fades away.
If you can't remember what app you'd like just hit ESC and Chuck will list the apps on your Mac (though I can't figure out what order they are presented in):
You can run Chuck as a normal app which shows up in your Dock, or just run it Dockless with just an icon in your Mac's menu bar (a tiny mustache! So cute!):
You can toggle the search panel, refresh Chuck's App list, or quit Chuck from here. Chuck's Preferences have a few tricks waiting for you:
Assign a Keyboard shortcut (by default nothing is assigned) or decide to run Chuck headless (no icon in the Dock or menu bar which means you would be missing out on all the sweet mustache action) from the basic preferences.
Clicking on Advanced gives lets you assign shortcuts to apps (so when I type in vpn Chuck finds my Cisco VPN app which someone thought would be a great idea to rename "Cisco AnyConnect Secure Mobility Client"):
Chuck requires OS X 10.6 or above, is free, and available in the Mac App Store.