Just got a handlebar mount for my Nextar X3 GPS. The instructions have WARNINGS and DISCLAIMERS about securing the GPS to the handlebars and recommend using a "strap" to provide additional security to avoid the GPS unit from being detached from the mount.
There was a recent thread about someone losing their GPS after riding over railroad tracks, turning around and seeing it laying in the road but watching it get run over by a truck before he could pick it up.
If you have a GPS handlebar mount, what, if anything, do you use to provide additional security?