I keep forgetting to watch Kevin Pollak's Chat Show, a weekly videocast that consists of Kevin Pollak sitting at a table and talking with a very interesting person who's in or around the comedy business. It keeps slipping my mind but when I do watch, I always enjoy it and think, "Hey, I oughta watch this more often." Here's a long, recent conversation with Dick Van Dyke. I sometimes skip over Mr. Pollak's intro chat with his staff but you might enjoy every minute of it…