In this 1996 Late Show clip, Dave stops midway through his monologue, grabs his cue-card boy Tony and travels to 30 Rock to lend an extra joke to Conan. Isn't it nice to see two late night hosts getting along?

Pretty hilarious to see Conan deliver one of Dave's classic set-ups, "I was walking through Central Park today and a squirrel..."

[via YouTube]

Thanks for the tip, Joanna!