I am kind of working in this field so forgive this shameless plug.

Look at http://help.oldmapsonline.org/. In this project we document and develop tools that can be used to put old maps online. One of them is our MapTiler (http://www.maptiler.org/). However, as you noted, if you want to create overlays your maps have to be georeferenced. There are two ways.

1) If your maps are not older than late 18th century and you know their projections and coordinate systems, providing coordinates of map corners is enough.

2) For older maps the usual method is by providing ground control points. Basically you mark the same locations on your map and some reference map. From this you can calculate distortion, affine transformation etc.

If you publish your maps as Zoomify (see the oldmapsonline.org site on how to do it), you can use our Georeferencer (http://www.georeferencer.org/) to do the ground control points georeferencing. Than you get KML for Google Earth and WMS which can be viewed in OpenLayers webviewer. Examples of both viewers are on the Georeferencer too. Or you can just download the worldfile that was generated and use it to crate GDAL VRT dataset or something.

I live in Czech Republic and we have had IDs ever since. I realy don't understand why are so many people complaining. In my country it is only a piece of plastic with photo, name, adress etc. I doesn't have a radio beacon that signals my position to the government. Neither it is used to gain acces to public places or to upload any data. It is used only for identification, probably in the same way as US citizens use their driving license. And of course by the police when they want to know to whom they are talking to. Where is the big deal then?