Alfred is free!
Launchbar is a terrific tool for performing tasks from the keyboard, without ever having to resort to a trackpad. But if all you use it for is to launch applications or open Contacts cards, Alfred does the job brilliantly. It can also take you to bookmarked websites, and if you type a search term, Alfred will allow you to search Google, Wikipedia, or Amazon by just by tapping †. It can also perform calculations, search the dictionary built into OS X for definitions, and even carry out basic system commands such as Empty Trash and Restart.
Alfred doesn’t have Launchbar’s power when it comes to accessing iTunes playlists, for example; nor does it have Launchbar’s built-in actions, but in all other respects it does a brilliant job and is an excellent free option.