If you frequently use 37Signal's Backpack web software, then chances are you don't like having to open a new web browser tab/window each time you wish to update your Journal. Logbook hopes to ease your woes by updating your Backpack Journal directly from your Mac OS X Menu Bar.
The application gives you a simple user interface with which you can update your status and add completed tasks. If you're having a hard time remembering to update your Journal, have Logbook remind you every x number of minutes, and only between certain hours. In addition, you can set a keyboard shortcut for showing/hiding the application in the menu bar. Your updates are sent using 128-bit SSL encryption.
You can purchase Logbook from the developer's website for $12.99. A demo of the application is also available.