grssom89 I'm not sure if you're referring to the SASE or the general costs of sending the letter to the US. For the cost of sending it, just go to the Post Office and tell them you want to send it to the US and they'll weigh it and put the stamps on for you. Unfortunately I don't know the answer about the SASE, as I've never had to send something abroad with a return envelope and postage paid. I guess you could ask at the Post Office, I'm sure they'll have come across it before. To be honest, if I were you I would probably send it without the SASE.
natty, on the other page of this thread I think someone has mentioned getting a reply from Gary Sinise and they used the CBS address. They do film at CBS Radford, so that address is still valid, whereas I would have no idea about whether the other two are still correct, it could be old information and he might have changed management or something, you never know. The CBS address seems like a good option to me.
General question about SASE for people who have sent them? If you sent a request for an autograph and enclosed a self addressed and stamped envelope, did they reply to you using the envelope you supplied or not? Just wondering...