I've been playing with my old eTREX, planning to use it for a short tour next week.
I wanted to put turn by turn instructions onto it, so had a play to see what tools are out there. I thought my findings might be of interest:
I found I could do everything in Route Converter, so it's almost a one stop shop for the eTrex.
http://www.routeconverter.de/webstart/en which runs in Java and does a nice job of converting between formats and can also string a route together from a series of Waypoints. It has a nice interface, allows you to add points, and crucially is easy to see your route and to add the necessary 60TR, 61TR, 63SO Audax type labels to the waypoints.
You can also edit Waypoints, remove superfluous points etc.
