Damn - thought I was the first to spot this!

I have the PDair aluminium case and modified it b opening up the aperture so it looks like one of the silicone hardcases. Pics are here

The PDair case is great but a little awkward to use; You have to unclip the hinged lid to slide open the keypad and you're not careful the clasp can catch the screen of the keypad is open. A screen protector is a must but would probably not protect the screen enough in the worst case scenario.

I found the cheap 'composite hardcases' on ebay OK but they needed a bit of finishing with fine glasspaper to open smoothly and the lugs broke off mine real early. I've never seen one yet with a neat join between the two case halves.

Looking forward to ordering the Otterbox - should be a good product.