Really the only way to get an autographed picture is at the cons. As of right now I don't know of any scheduled but he usually does quite a few over the year. I will post any appearances as soon as I am told about them.
Thanks Kay I just found out about Bubbafest which is August 11th. I'll make sure to get that up in the news section. Also, Lee will be appearing at the Crypticon in Minneapolis at the end of October.