I was talking to young Scampy at lunch yesterday, and we talked about the theory of having two passports. There are a few reasons why you might need two passports (working in Israel and Middle Ages countries), abusing the postal visa service or simply wanting to keep those whole page Cambodia visa stickers all in one passport.
Can you have two current passports for the same country? Many people have two for different countries, so I can't see why not.
If I applied for another one at the lovely British Embassy in Bangkok, would I need a police report saying that it had been stolen, or could I just tell the passport issuing office that I want to go to Israel and they would give me a knowing wink and just process the application for me?