I PM'd once with one of my favorite pornstars on the board and she gave me a nice reply.
I also got a nice letter from my congressman after having written him a few years ago.
As far as email, I did once send an email to Billy Corgan of The Smashing Pumpkins (my favorite band) and he gave me a nice response.
Oh, and yes, I once sent a telegram to Britney Spears:
"I hate your singing, stop. <stop>"
She emailed me: "You didn't have to tell me to stop twice, I got it the first time!"
Guess she doesn't get many telegrams.:dunno: