Version 3 of the Google Maps API adds support for styled maps, which means it is now possible to hide features or display them differently on the base map. This could lead to some interesting customisations, and also leads to some questions about how exactly Google have implemented this? Are they creating map tiles on the fly? Or have they stored every possible permutation of styling? Surely the former, but how come it doesn’t seem to make any difference to the performance of rendering?
Anyway I had a play with the styled map wizard (which doesn’t work in IE for some reason) and thought I’d experiment with a map displaying just rail lines. And I kind of got this working, but there was a fundamental problem. Rail lines are only displayed when the map is zoomed in below a certain threshold so the map wasn’t any use to get a broad overview of rail lines in the UK for instance. And the styled maps API doesn’t seem to provide any control over this thresholding.
So it looks good as an initial implementation, but I think more control is required to be a completely useful API.