Pineapple Express is written by Seth RogenSeth Rogen wrote Superbad. Superbad is starring Emma StoneSuperbad is written by Seth Rogen
[Human]: I enjoyed the movie Pineapple Express.  Can you tell me a couple of the actors?  I can't seem to remember. [Assistant]: Sure, I just watched that the other day.  I love it, too.  James Franco and Danny McBride are in it, as well as Seth Rogen, that guy from Knocked Up. [Human]: Can you tell me some other movies Seth Rogan was in...he cracks me up. 
Oh yea, he's pretty funny!  I know he was one of the writers for Superbad.  He was in Step Brothers, he was a voice actor for Kung Fu Panda 2, and he was in This is The End, which is hilarious.  And Fan Boys, a  silly movie about star wars fans.