For the Garmin 2610, I have a track to route converter on one of my websites, here are the directions.
The basic process is:
1. Download your tracks into Mapsource from the GPS, saving the file as a .gpx file.
2. Go to http://www.rydinshotgun.com/app2 and click on "Track to Route Conversion". Click on "Browse" to locate the file, and then click "Upload File for Conversion". The converted file will be displayed to you in a text box that allows you to copy the contents (click anywhere in the text area, press CTRL-A to highlight, right click and copy)
3. Replace the original .gpx file contents with the converted file and save it. Another way is to run notepad, paste the contents into it, save it as a text file but name it with the gpx extension (e.g. xxx.gpx).
4. Read the converted file into Mapsource and you will see your tracks as routes. At this point, you can rename and download the routes to your 2610.