The closest you can come with built in capabilities is to use "Full keyboard access", that you can find under Keyboard in System Preferences. That gives you the opportunity to activate the Dock from the keyboard (F3). Then you can navigate the Dock with the arrow keys, and activate or launch the selected application or document with return or enter.
It's a crappy solution compared to LaunchBar or LiveSearch. I use LaunchBar, and recently installed LiveSearch on my other computer, it actually seems to be even better than Launchbar. More options and features, and just as fast. Try them out, they are both shareware, so you can use them for awhile before you have to pay.