I couldn't find a good general thread on GPSr mounting options so here's my two cents...
Most GPSr manufacturers offer mounts for their products but the OEM mounts don't offer much in the way of vibration resistance and lack flexiblity particularly if you want to move your unit between vehicles (car, truck, atv, snowmobile, boat, or plane). There is a better way...
Check out RAM Mounts: http://www.ram-mount.com/
They have kits for most portable electronics that offer suction cup, surface, handle bar, and other mounts in many different configurations. You can even get them to mount laptops in your vehicle! If you move your GPSr between "vehicles" you can just buy additional bases instead of another whole kit. This enables you to move 90% of the kit you already have back and forth with ease.
You cannot buy direct from RAM Mount. The place that I found to have the best inventory and has, so far, been great to do business with is: http://www.custommounts.com/
I picked up a surface mount kit for my GPSMAP 60Cx. This mount is great! It's well built, offers great flexibility in positioning, and absorbs vibration very well. It also allows the use of ALL OEM cables!
Another of my favorite accessories that makes mounting things in a car or truck much easier is a Vehicle Specific Mount from
Pro.Fit International: http://www.pro-fit-intl.com/vsm.html
I order these through my cell phone company. This is the product their installers often use. Many fire/police radio installers have them as well. These brackets often provide the only good way to mount things on a dash in new vehicles.
Hope this helps...