LaunchBar is a popular and long-lived productivity-enhancing app that can literally change the way you use your Mac--and that change can come gradually, as you learn the app's many tricks and secrets, bit by bit. At its most basic, LaunchBar is a completely keyboard-based way to find and open anything on your Mac with a few quick keystrokes. But its functionality goes far beyond that, letting you use keystrokes to manipulate files, send e-mails, search Web sites, and control apps like iTunes.
LaunchBar has an almost invisible interface, and you invoke it with--of course--a keystroke, which by default is Command-Space, the same one shared by Spotlight. You can almost think of LaunchBar as the ultra-pro version of Spotlight, and like Spotlight it pulls up suggestions as you type in characters (Mail for m, for example) and you open a specified app or file by pressing return. For the most part, the similarities end there: you can type in a few letters of a contact and that will pull up their address book entry, or with a quick couple of arrow keys, you can open a new e-mail to them or start an IM conversation. You can quickly search Wikipedia, Google, IMDB, or Merriam-Webster (or pretty much any site you want, using customizable search templates) before even opening your browser, and access a huge list of built-in actions that can let you do everything from restarting your Mac to pausing iTunes to making a TinyURL with just a couple keystrokes. LaunchBar even serves as an ever-present scientific calculator (just start typing numbers), a clipboard history (giving you access to up to the last 40 items with a couple taps), and a plain-text event and to-do creator for iCal. Best of all, LaunchBar learns from your behavior and helps you get to your most-used apps and actions more quickly.
LaunchBar's biggest drawback is probably the sheer breadth of its features, and you can still find surprises after using the app for years. That said, LaunchBar can have a huge impact on your work flow even if you're using just a fraction of its capabilities--and the app's excellent documentation can let you drill down as far you want. Some apps offer similar features (including a few free ones), but none come close to delivering LaunchBar's stability and adaptability. LaunchBar may not be cheap, but in terms of productivity, it can offer a huge return on investment. It's the kind of app that you wonder how you ever lived without.