Alongside patenting of items and copyright there is a fairly new British protection called Design Right. If you were to design something which was completely and totally original Design Right would protect the physical shape of that item from being copied. Although Design Right will not cover you for any 2D images you may have designed, the cover it does offer for other original works can last a fair amount of time, 15 years after the design was created and 10 after the design has been first marketed and sold. If however, someone was to use your idea without your permission you would need to be able to prove that the works were original, that you were the first to create it and that any copying of the item had been deliberate. Below are links for more details on Design Right.