Demo: http://ec2-107-21-232-84.compute-1.amazonaws.com/static/laio/index.html

A super-hacky overlay for leaflet[1] that lets you display an image on top of
the map, transform it using three anchors, and output ground control points
you can pass to gdal_translate.  (Rule #2: Inspired by Chris Broadfoot's 
overlay-tiler[2].)
      
This should probably end up as a Leaflet layer object that you can add with
map.addLayer(), but until then, there's this joint.

[1] http://leaflet.cloudmade.com/
[2] http://code.google.com/p/overlay-tiler/

Look at index.html and style.css for a usage example.

Works in Firefox 10, and Chromium 17.  Probably breaks on some other browsers.