Pre-pre-alpha and so likely to change from day to day, or break, here’s the project I started a while ago and have been working on getting usable, but you should be able to have a play on this sneak peek at least. It’s an open source map georectifier / warper, written in Ruby-on-Rails and using GDAL, Mapserver, and OpenLayers, and it’s provisionally called “Map Warper”. It can be found here: http://wrp.geothings.net
Inspired by Metacarta’s Map Rectifier, which I have written about here and here, it was originally primarily planned to be able to support the WMS plugin I developed for the JOSM editor, and also to assist OpenStreetMap surveyors who collect and want to use their own ground control points. (The other driving force was the desire for me to use some fine out of copyright maps and make a free geodataset of Roman Britain, and historical features in general)
It will have additional features in the near future, such as enabling TileCache for WMS-C/TMS, export to Google style tiles, GeoRSS and KML, amongst other things. As mentioned above, it is still unstable and in active development, so things will change and your data probably will be deleted!
We’re looking for a nice name for it, and a nice logo would be good too!