I'm looking for a site which allows to you look at a street map of
areas of London with restaurants marked and click through to more
information (style of food) and ideally reviews of the restaurants. 
There are millions of sites where you can work the other way,
searching on a restaurant name or style of food, even within an area,
but I can't find one where you can start from a street map.  I'm
actually interested in Fulham/Barons Court/Earls Court/West
Brompton/Chelsea at the moment (especially round North End Road from
West Kensington down to Fulham Broadway), but a tip for a site which
lets you choose other areas of London by name or postcode.

I want it to be able to choose somewhere to eat within easy walking
distance of a hotel.

The definitive map reference in the UK is www.mutlimap.com  CHoose
your location and select the drop down items of interest in your area.
It will give you nearest hotels, restaurants etc. It will even give
you directions from one location to the other. I live in the UK and
could live without it.

Thank-you - I've used multimap often as a map, but I'd never tried the
"find a restaurant" bit.