There is a freeby paper given away in London (and other British cities I guess) called the Metro. Whilst on the tube yesterday I espied an article so I picked up one of many discarded copies to read about "Cyril the Squirrel".
Apparently Sue Britton had feeders hanging from a frame (the photo in the paper shows this the online one doesn't) and it was "squirrel proof". Cyril noticed that the Britton's subsequently put up a basket of flowers hanging from the frame.
One afternoon Cyril hopped onto the rail and on to the basket and used the momentum of the swinging basket to reach the feeders!
The North American Grey Squirrel is not well liked over here due to its out competing the native red and spreading squirrel pox throughout the red population but you just have to admire their ingenuity.
There's a photo on the link.