How about a premium membership to Were Alive. As a paying member you could listen to the podcast a few days earlier. Have yaccess to a separate stream for live events that won't crash. Get access to mini stories.

I would also buy a dvd for the making of We're Alive. Give tours of all the sites, Army base, Fort Irwin, Mallet Mall, ground zero. Video of the live performances

Market a line of Zombie miniture figurines

I would also pay for customized audio clips I could use for ring tones, answering machine messages and online gaming.
Scratch voice: Duffusmonkey has a surprise for you.
Burt voice: This asswhipping has been brought to you by Duffusmonkey
Announcer Voice: Duffusmonkey would go through the appocolypse for you will you marry him
Announce Voice: Duffusmonkey is fighting for his life please leave a message
KC Voice: Duffusmonkey hated that movie more than I did