The other nice thing about OpenStreetMap is, not only can you upload your GPS data to help out the mapping project cause, but you can also download the map data to your GPS device as well; something you can't do with Google Maps or MapQuest. In addition, OpenStreetMap seems to contain a lot of bike and hiking trails that you don't see in most online mapping products:
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Thus, OSM offers a less expensive alternative than paying Garmin $100 for their Street or TOPO maps. While the Garmin maps may have more features, like routable trails and more POI's, it's nice to know there is a less expensive option available.
If you are primarily interested in acquiring free trail maps for your Garmin GPS device, and you happen to live in, or will be traveling to, the northwest, then you'll want to check out Northwest Trails, created by cacher, Moun10bikes. If you're looking for a similar mapset for the greater Arizona area, then checkout the Southwest Trails site, created, ironically, by "GoNorthWest".
For GPS maps of most other locations, I strongly recommend the GPS File Depot, which I've mentioned in this blog numerous times in the past.
Speaking of crowdsourcing, you may have noticed Google's announcement that they are now using crowdsourced GPS data from people using Google Maps Mobile to update their real-time traffic data on Google Maps.
And finally, a big shout out to EMC of Northridge, CA for setting the record the other day for the number of caches found in a 24-hour period: 413! It took me years to find that many, and she and her pals did it in one day. Amazing.
Cache On!