While the Writer's Tools extension for OpenOffice.org is developed and maintained by your truly includes the Visual Word Count tool, it does have one serious drawback: it uses a modal window, i.e., you can't do anything until you close the Visual Word Count window. Fortunately, there is an alternative solution that solves that problem. The Live Word Count macro for OpenOffice.org is written in Python, so it uses a non-modal window which can be opened alongside the current document. To install the macro, create a folder called python in the /home/USER/.openoffice.org/3/user/Scripts directory (where USER is your actual user name), grab the latest version of the script and put it in the created folder. To run the macro, launch OpenOffice.org Writer and choose Tools | Macros | Run Macro. Select then My Macros | wc | wordCount and press the Run button.

Instead of navigating through the menus every single time you want to launch the macro, you can create a menu item for it. To do this, choose Tools | Customize and select the desired menu (e.g., Tools) from the Menu drop-down list in the Menus section. Press the Add button and select the OpenOffice.org Macros | My Macros | wc | wordCount macro. This adds the macro to the selected menu. You can then use the Up and Down buttons to move the created menu item. To change the item's name, press the Modify button, choose Rename, and give the menu item a descriptive name (e.g., Live Word Count). Press OK, and you are done.

Thanks to Leif Lodahl for the tip.