I started on something that does this a while ago as part of another project I am working on, you can try it out here
http://www.griffin-helicopters.co.uk/landingsite.asp It isn't finished and the fuel and fees bits aren't wired up yet but I am sure you will get the idea.
It will be up and down over the next few days so if it doesn't work try again later.
Particularly useful can be the nearest landing sites to Lat Long / Grid Ref.
There are 1400+ sites in it at the moment, some are airfields, some hotels, helipads pub etc.
I can create an editable comments list for each one quite quickly. might come in useful. I'd be interested to know what people think.
Gary S.