Gordon suggested that it might be useful to have a sticky where we can post details of people who we have proved (rather than who have suggested) they can provide a useful service, so I'll kick it off here with:
Duncan at FobFix.com. He turned around a very battered water damaged P38 fob in a couple of days, working, tested, recased and key number identified.
Worth getting in contact with, as long as you actually have a fob, no matter how battered or not working. He doesn't do new fobs or convert fobs from other P38's to work with yours so don't expect miracles, but if you have a non-working fob for your actual vehicle, well worth getting in touch with.