Its odd that it's not a standard iOS feature to cancel a UIActionSheet by tapping outside/above it, and it's actually a bit tricky to code it. But here it is:
Thanks for reading! And if you want to get in touch, I'd love to hear from you: chris.hulbert at gmail.
(Comp Sci, Hons - UTS)
iOS Developer in Sydney.
I have worked at places such as Google, Cochlear, News Corp, Fox Sports, NineMSN, FetchTV, Woolworths, and Westpac, among others. If you're looking for a good iOS developer, drop me a line!