Be Excellent To Each Other

Yes.

So say I want to get onto google maps (or equivalent) and start a straight line at for example Brighton and finish it in Grimsby, with the ability then to zoom in and see all the places along that straight line... how do I do that then?

Because I don't know.

Could you do this on gmap-pedometer.com ?

A hi-res image file map of UK dropped into photoshop?

Sorry, don't know of any apps that would do that. Failing that, go analogue. Get a road map

I'm going analogue anyway, but I can only have a map so big for that. I'm potentially interested in finer details, villages, specific places along the route and aerial photography would be interesting as well.

Googlemaps maybe not, but you can do this in Google Earth.

Problem solved

Google search, first result has a link to: http://www.localsearchmaps.com/routeplanner/

Click on the map where you want your markers, then click on 'Get Best Crow Route'.