I just cleaned my microwave and thought I'd share my method. Get a cup of water put a couple of slices of lemon in it. Put the water in the microwave and heat it until it boils - let it stand for another minute or two - take the cup out and wipe over the microwave with a clean cloth. The steam will have softened everything up so it comes straight off. If anything is stubborn repeat the process. The lemon makes it smell all fresh and there's no need for harsh chemicals that are bad for us and the environment.
Does anyone else have any handy hints they want to share?