Open Geo Data/Sources

Getting hold of data

GPS traces
 * via http://openstreetmap.org/ GPX upload facility
 * from geowiki's repository?
 * from the London Free Map projects

Out of copyright maps
 * the OS New Popular Edition of 1951

Satellite base imagery
 * Landsat - public domain, 15m/pixel
 * Ikonos - reasonable cost, 1m/pixel, no online redistribution but no restrictions on derivative works. http://www.spaceimaging.com/

Gazeteer/geocoding data
 * LSCES contains some global data including lists of UK places (sourced from NIMA?) and postcode outcodes: http://home.lsces.co.uk/ibWebAdmin_0_98/FirebirdFederationDataArchive.html

Sharing data