I got to spend some time talking with him once when we were both visiting the offices of OLPC in Cambridge, more or less across the street from MIT's building 32 where CSAIL is located. I told him a little about what I was working on (learning agents attached to dialogue systems) and he had some insights. I ran out to the coop to buy another copy of The Society of Mind and he signed it. We also talked a little bit about some of the ideas in his The Emotion Machine, which I hadn't read at that point.
On top of his work, Minsky taught me that you should meet your idols. If they're worth it you walk away enriched and invigorated.