OpenStreetMap
The OSM based topo map project ("TopOSM") that I've been working on for a while was recently announced on the talk-us mailing list, and I got some good feedback.
The map can be found at http://toposm.com/
It was also picked up by some blogs and news, such as:
http://vector1media.com/spatialsustain/developer-creates-beautiful-massachusetts-map.html
Additionally, I created a wiki page with a description of how the map was created, including the scripts and style definitions used:
http://wiki.openstreetmap.org/wiki/TopOSM
It's still work in progress, so I'll keep improving it until I'm either satisfied or bored to death. :)
Discussion
Comment from Aubanel on 5 May 2009 at 12:17
Holly crap, that is awesome ! That's the best ever digital map I've ever seen, we should definitely get that as one of the official layers is osm. Thanks for this amazing work.
And you call that work in progress... cannot wait to see what you are going to improve.
Comment from Ahlzen on 6 May 2009 at 00:39
Thanks!
Well... adding it as an OSM layer would be nice. :) Unfortunately, the elevation data isn't available for all countries, or even all US states. In fact, there are probably places in the world where this type of data just doesn't exist. This map has much higher detail in the topography than e.g. SRTM (which *is* available for the entire globe).
Currently TopOSM is Massachusetts only, but if I find similar data for other areas, I might render those areas as well.
Comment from AshKyd on 6 May 2009 at 07:47
That's a really, really hot map. For countries sans-elevation data, would it be practical to create some kind of estimation from the altitude data in uploaded gps traces?
I was thinking about this a little while ago, it would be especially useful for the cycle map in urban/suburban areas. I know I've been badly caught out on massive inclines because the cycle contours aren't all that distinguishable, at least. :)
Brilliant work though, you deserve a beer/preference. :)
Comment from Ahlzen on 7 May 2009 at 00:49
Thanks for the compliments! I'm glad you like it.
I guess estimating elevation from GPS tracks could work to some degree in densely populated (and GPSed) areas, but overall I think there are few areas where it would be better than even SRTM. It might work for detecting and labeling steep inclines along roads, e.g. for a cycle map (as you mention), though. Could be a fun project.