YOu know, I thought microchipping was fabulous until I got to talking with some dog owner friends of mine. These are people that have many years of experience raising dogs, and shipping them overseas because they are show dogs, so identification is very important for them. Anyway, they are starting to have problems with microchiping in some cases. It has been found that the chips will move, as in when you go to scan it, it won't be on the back of the neck anymore. One of my friends was getting a health check done on her dog, and they decided to check the chip too. When they finally found it, it was low down on her left shoulder.
Also, and this hasn't been confirmed yet, just supected, but it seems that dogs/animals with a microchip are more susceptable to certain types of cancers. Personally, I think I would get my rabbit tattoed. You can use any numbers or letter you want, even your phone # or last digits in your social sec. number, or whatever. Then make a record of it with your vet, so that it can be verified if your rabbit is ever lost or stolen.
Just my two cents, anyway. LOL