The KaZoo cases are made of silicone although Griffin also make hard clip on cases.
I think we both chose the right colour of case to go with our iPod colour. The turtle case is much more bulky than the owl and pressing the lock button on the top is quite difficult. The KaZoo cases aren't really for you if your more practical but I have another case to put my iPod in when I go out so that isnt a problem for me.
They cost £24.99 and available to buy from the Griffin's website.
What cases do you have for your appliance?