I don't do service journalism well (or at all, reallyI'm allergic) but a reader offers the following advice: "Some tips if you are going to approach a celebrity, especially a character actor, and not make a Bob Morris-like fool out of yourself:
1) Know their name. It scores HUGE points (alas, we missed on this count, but at least we didn't go "Hey! You're that guy! From that show!")
2) Go ahead and compliment them on their work, (e.g. "We love Oz. You're great"...), but know something OTHER than what they're semifamous for at the moment (e.g., "and we loved Shakespeare in the Park, too.")
3) If you can do it without pulling up their IMDb stats on your webphone, ask about a classic they worked on long ago; you may unknowingly score points for bringing up their first movie. (e.g., "Honestly, was Barbra Streisand a raging bitch on the set of 'What's up, Doc?' Come on, you can tell us.") Ok, we didn't put it quite like that, but go ahead and try it."