As others said, you can, it will work, it is, well, not really legal, but Apple has sold you an expensive product that you can't use if you don't have either Leopard or Snow Leopard, and Apple doesn't sell Leopard (10.5) anymore, so as a social experiment, you could go to the nearest Apple Store, tell them that you bought an iPad but you only have MacOS X 10.4, do _not_ tell them that you want to buy Snow Leopard but just ask them what you should do to get your iPad working, and I think chances are excellent that they will advice you to buy Snow Leopard for $29.