FullyFlapped, have a look at OziExplorer (havn't got the url to hand - I'm at work) but you should find it easily on a search.
You can scan in A4 or A3 overlapping sections of a chart, stitch them together (quite straightforward) to form the original chart. You then "calibrate" the image so that the coordinates are known all over the image surface. You can then have moving map, waypoint management, route planning etc.
PM me if you want more info,
Rgds
Fuji
