“I am buying a mobile home in FL. I live in PA. My mother is dealing with the owner. The closing will be on February 11,2007. I will not be there yet. Is my mother able to sign the papers for me? If not, can we do this over the phone so I can give my verbal permission for her to sign the papers?”

You need to check with the person who is handling the escrow. Typically, this is handled by having you execute a power of attorney giving your agent (in this case, your mother) the authority to sign for you.