Conversation so far:
What was Zach Galifianakis' first mainstream performance?
Galifianakis played Alan Garner in the hit comedy The Hangover
What other roles did Zach Galifianakis take after The Hangover?
He was also prominently advertised in subsequent films that featured him in supporting roles, such as G-Force, Youth in Revolt and Up in the Air.

Question: What role did he play in Up in the Air?
Self-contained rewrite: What role did Zach Galifianakis play in Up in the Air?