I am a former user of Quicksilver (another great application launcher), but as Quicksilver apparently (I’ve never seen an official statement from Blacktree) is not under development anymore I decided to try out Alfred as a replacement. At it’s current state it’s not as advanced as Quicksilver, but several of the most advanced features of Quicksilver were actually not needed in daily operations. Alfred has some unique features up it’s sleeve and is easy to use, configure and customize. The developers are actively releasing new versions with bugfixes and new features.
In order to utilize the application to it’s full potential you’ll need the Powerpack.
Currently it’s priced at £12 (special beta price).
Support the developers and buy it. The iTunes Mini Player is worth it all alone.