My ds could keep himself busy all day with the cushions from our couches. They can be caves, water, pirate ships, anything!
He also *loves* to cut up my junk mail. I just give him a pair of kid scissors and let him go to town.
Making people out cardboard toilet paper rolls is fun too. Just cover the roll with construction paper (or leave it plain) and color faces and clothes on it. Cut out strips of paper for arms and legs and glue them on. We made Peter Pan and Captain Hook a few weeks ago and have had lots of sword-fighting fun with them.
When I am all out of ideas I let him play in the tub while I sit in the bathroom with him and read a magazine.
Thanks for the orange bird feeder idea. I'm gonna have to try that!