Fantastical 2 for iPhone Released
If I wasn't already fairly happy with Calvetica ($2.99 in the App Store, recently updated for iOS 7 as well) I'd definitely be taking a look at Fantastical 2 for iPhone ($2.99 in the App Store).
I use Fantastical on the Mac($14.99 in the Mac App Store) and love it's use of natural language for entering events.