What a cutie! I'd inform the local humane society and maybe leave a poster there, but no way would I drop him off there. I found a cat in the countryside once and took it to the humane society, telling them that I wanted to adopt the cat if the owner was not found. They told me to come back the following Monday and when I did, they said they had put the cat to sleep already
. Not all humane societies are the same, but I don't take any chances any more.