You can upload routes to your portable Garmin units with Rocketroute!!
I have tested this with a Garmin GPSmap 296
What you need is a portable Garmin Unit and this free software:
http://www.easygps.com/download.asp
Then export your RocketRoute to .GPX (note: do not select Garmin .FPL format). Start Easygps and open the GPS file you just created ADEP_ADES.gpx Then click on upload using this software, this software is free and works really well