OK so I have downloaded all of the free O/S data and trying to work out what to do with it :-)
For a start, the 1 pixel per m² street level map tiles are fun. They are done as 5km x 5km tiff images, so I'll be re-tiling them I think. They only show road and building data not general terrain, etc. But are rather fun.
Royal Mail must be pissed though - as they charge for postzone (postcode to grid ref mapping) and O/S just gave it away free :-)
OK... rant - some of the O/S grids use lower case filenames and some use upper case and no consistency. Arrrg!