TakItWithMe is a free service enabling anyone to easily take your Google MyMaps and Google Earth content to Garmin devices -- there's also a Direct Mymaps and KML conversion routine available!

The TakItWithMe team has put together a very slick demo (YouTube video) showing the application in action and all of its simple-to-use functionality. See http://earthnc.com/introducing-takitwithme. Watch as they conduct a simple real estate search (near my old digs in Destin, FL)  in Google Maps, create a  Google My Map of the result, and send it to a GPS for use while house hunting.

So, what can you do with the application?
Use the service for uploading Google My Maps and Google Earth geo content to Garmin and other handheld devices. Anyone familiar with using Google Maps or Google Earth can transfer online map content including points, routes, geo search results, and Google Earth files to their Garmin GPS device of choice with the simple click of a button. Imagine... create all you POIs or routes within Google Maps and easily take them with you.

TakeItWithMe is a free service and supports most Garmin hand-held devices by leveraging the newly announced Garmin Communicator API. Because the Communicator API is currently limited to Internet Explorer and Firefox on Windows, TakItWithMe also supports online map conversion to the GPX format - compatible with a wide range of GPS software and devices across operating systems.

Because the Communicator API is currently limited to Internet Explorer and Firefox on Windows, TakItWithMe also supports online map conversion to the GPX format. 

One of My Google MyMaps as seen using in Google

MyMap taken over and dropped into the TakItWithMe Converter

About The Garmin Communicator Plugin API
The Garmin Communicator Plugin API is a browser plugin and JavaScript support code that allows developers to transfer location data – such as waypoints, track logs, maps and points of interest (POIs) – to and from a website and Garmin device. The benefit of this service to the retail consumer is that the API will simplify loading location data to a Garmin GPS. For example, on MotionBased.com, customers can quickly upload their activities (track logs) from the GPS.  The cross-browser, and soon the cross-platform plugin, provides a consistent experience for MotionBased customers.  Geocaching.com also integrates the plugin so that users can easily transfer selected geocaches (waypoints) to their Garmin device by clicking a new Garmin icon on the Geocaching.com website.
http://developer.garmin.com/web-device/garmin-communicator-plugin/

• http://maps.google.com
• http://earthnc.com/introducing-takitwithme
• http://www.takitwithme.com/