Actually I did it with the signature of my boss. He forgot to sign an important document on his first day of his holidays. So he called me from Croatia. After discussing matters he asked if I would just "copy" his signature from another document. I tried but I could not convincingly forge his signature. In order to be looking ok it had to be in blue ink. I had to resort to my knowledge of software and a high resolution copy. It took me almost an hour. The document looked ok. I did send it to him and he approved. Since I am a practical witch I kept the file. No, I didn't forge cheques to let the company pay my dues. But on two further occasions the sign in the file was useful and handy.