Ok, . . . I've been watching this thread . . . You have to make two distinctions: 1) Is it for "finding your way back home"? 2) Is it for "production mapping/cartography" and the above? If it is for (1) then any old GPS unit from $100 to $500 will do just fine . . . for most people that is all they will ever need. The higher-end models in that range will allow for color display of background/basemap/topo images and of course that is cool and can be of assistance in a variety of situations. Normally this kind of device can be mounted on the bars using a variety of mounting devices. I've found it very much "in the way" in with most devices. If you want to make a "real" map of a riding area using GPS, plan on spending $5,000 to $10,000 for the appropriate equipment, associated software, and possibly base mapping layers. The cost is high, but the results are amazing!!! We've used Trimble GeoExplorers (in a small backpack) with a remote mounted antenna on the helmet and have captured some incredible trail detail at a very high level of accuracy (+/-40 feet). Because the data is captured using this methodology in a know coordinate system you can easily overlay it on basemapping from www.topozone.com, www.terraserver.com, or if you live in Kentucky using basemapping for FREE from http://kymartian.ky.gov/. The results allow for the publishing and sharing/selling of "trail maps" to interested folks . . . you can obviously find your way back home with this sort of device as well. I think it is cool that the off-road biking community is embracing this technology!!! Very Nice!!