try this one
http://www.hp.ca/catalog/accessories...Covers&lang=en
its an offical hp hard case (plastic), i am currently using it
it does make the ipaq more bulky but since its made by hp everything fits and you can sync with it, i do. it gives me the peace of mind that if i drop it i will not damage the unit itself caz it pretty stedy and stong.
also it will fit in the the carry belt pouch that came with the ipaq
good luck