Fantastical for iPhone
Flexibits has released an iPhone version of their popular Fantastical app, previously only available for Mac.
I wrote a review about it here, but I wanted to see what you guys think about it. Personally, it's my favorite new calendar app. I've been using Agenda Calendar until now, but Fantastical is so much better for creating events since it uses natural language.
If you don't like Fantastical, tell us what other calendar app(s) you're into! :)