In reply to Tony the Blade:
Again, if you're just after protection, then I chuck mine in a small Exped dry bag, along with wallet and car keys.
Then again, I've cycled for many miles with phone (and cash and cards) in a zip-lock food bag in back pocket - cheap and effective.
I've got an old Aquapac roll-top case that is brilliant, but too small for modern phones. They've never brought out a larger size, annoyingly, as I'd definitely buy one.