Making and sharing maps

The second great advantage of National Geographic's proprietary system is that they have engineered a way for map buyers to annotate topo maps. Users can download their travels via GPS onto maps, and then add comments. Then they can print out their customized maps. This ability to interact has pumped some juice into mapmaking, It is flowing most visibly in the National Geographic's MapXchange, where folks can swap their annotated maps. Dedicated hikers can post their map additions. ... Other user-generated maps offered on the exchange: Waterfall hikes in Georgia, photo trails in Utah, mountain bike trails surrounding Santa Barbara. All free for the taking -- but you need the Topo software to read and use them. (Bummer.)

A shame, but as Kevin says, it's just a taster of what's on the way:

What is likely to come along and overwhelm [National Geographic] is an open source version that allows anyone to download the software, add a level to a map, and then swap it. Just like in music and films where file swapping is rampant, money will be made in selling additional and premium services.

The present is just as exciting. Amateurs are learning the language of mapmaking -- the nuances of projection and scale. Someday soon there will be a MapCon, a convention of map fans, fanatical devotees of amateur map making, none of whom are professional, and all of whom are making maps others use.

(In case you're not aware, there's loads of interesting stuff happening in the world of grassroots mapping at the moment that complement these ideas.)