Updated April 6th, 2010 Garmin have just released several updates of interest, v3.01 for the BaseCamp PC Software and software updates for their recent handheld GPS systems : v3.70 for the Oregon, v3.30 for the Colorado and v2.80 for the Dakota. The update for the handhelds combined with the BaseCamp update gives users access to the new BirdsEye™ Satellite Imagery maps.
This is a somewhat fancy name (with a fancy "Bond" logo!) for the satellite maps we have become familiar with thanks to Google Earth and Google Maps. While you can download them to your computer for free if you own one of these handhelds and connect it over USB, a $25 yearly subscription is required to transfer them to your device and use them in the field. A side benefit of this BaseCamp update is that nuvi owners will be able to view their maps on their computer too. More details and screenshots in the Garmin BaseCamp Topo PC Software - v3.01 topic of the "Handheld Portable GPS Receivers" forums.
Updated November 29th, 2008 - In the past we were the ones figuring out tricks to add topo maps to Garmin road units and that was limited to vector maps (see below for details), but Garmin surprised everyone yesterday when they published a method on their blog to import raster (i.e. pictures) maps into their latest handheld GPS receivers, the Colorado, Oregon and Dakota. Amazingly enough, all it takes is a scanned paper map and...Google Earth, so it's likely some tool will quickly be available to convert existing Ozi maps...
... (probably the most widespread format) to Garmin compatible maps. In the meantime you can use the Garmin's Guide for "Custom Raster Maps" of the "Handheld Portable GPS Receivers" to discuss and share tips.
Updated November 29th, 2008 - Forum member Boyd "does it again", after sharing a tip to navigate with topo maps on his SP2620 four years ago, he just found a way to add contour lines from topo maps to the standard City Navigator road maps used by the Garmin nüvi systems. This transparent layer can be easily toggled in the map settings. You can make your own contour maps by following the guide he posted in...
... this topic of the Garmin nüvi forums on GpsPasSion.
Posted October 7th, 2004 - It looks like October is going to be a "topo month", with new software releases, new articles and user feedback! Site member Boyd , shares with us in this thread of the Garmin forums how he was able to put the US topo maps to good use on his SP2620 while driving in areas where the Navteq coverage provided by CityNavigator just wasn't enough. This should also work on the recently released Quest. Of particular interest is the "trick" he points out that lets you combine CN's turn-by-turn route calculations with the detail rich maps of Topo USA. Details and pictures here.