Dan - some useful information, and a list of hillclimb/sprint (hillclimb on the flat!) venues at
http://dspace.dial.pipex.com/ian.cro...t/sprints.html
Not quite sure where Berks is (!) but most hillclimbs are in the SW or North - Loton might be your nearest - just over the Welsh border. There's probably some sprints nearer.
My favourite hillclimb: Wiscombe, but it's so damn far! Is Porlock still going - I hadn't heard anything about for a few years - always fancied doing it - can anyone point me to the organisers website?