Annie Hall.

Just watched Annie Hall again. Funnier than I remembered. But I was just looking at the cast list on IMDb to verify that it was Jeff Goldblum at that party (it was) when I noticed that, playing the Truman Capote look-alike (in the park bench scene where Annie and Alvy describe passersby) was actually Truman Capote. It's things like that that make me realize 1) how small the world is, and 2) how starved for attention certain people are.