Exporting Data to TomToms
People who go geocaching with TomToms (or more likely driving to them, as the TomTom software isn't really great for geocaching itself, but for driving it's fantastic), there is special support for creating TomTom .ov2 files. The result is maps that tell you exactly what is around you:
From the main menu, use the "export" button:
From there, select the "tomtom database files" option
The next screen will let you select the caches you wish to export (as well as some other transformation options). When you click on next it'll create a bunch of files that should be copied to your TomTom data card into the map directory. You'll also need the .bmp files that come with the GeoQO software.
(future work: help you install these ;-)