Been using the mac calendar app Fantastical for awhile, and just realized there is an iPhone version. This is a $1.99 app, and well worth it. Natural language ability to add events, and a very cool calendar interface. Well worth it, and much more user friendly then the default Calendar. Sadly, no iPad version. But $2 well spent.
http://flexibits.com/fantastical-iphone
http://flexibits.com/fantastical-iphone