The Robot and the Tramp

Ever since I saw Richard Attenborough's film Chaplin I have loved the comedies of the man himself. Earlier today, while reading a blog (the name of which I have, unfortunately, forgotten), I read a review of the newly released film Wall E. Films about cute robots - wasn't that done in the eighties? Anyway, I had heard of the picture already and thought no more of it; not my thing. However, the blog I was reading suggested that Wall E bears some resemblance to the Tramp. Here is the latter being clever.

Can anyone tell me how he never falls over the edge?!
And here he is being just plain funny.