Crows as well. One radio report I recall discussed how they not only recognize human faces but can inform others about individuals that threaten them. The researcher who was featured has to wear a mask when he is performing experiments or else he risks being attacked by other birds while walking around campus...
Problem for octopi are that they are not social animals, so their intelligence consists mostly from problem solving.
actually they can communicate by changing colors as I understand it
sounds almost like me :)
I don't know if there is any truth to this, but I have heard that octopus have a "different" sort of intelligence than we are used to. It's more innate to them, so they are capable of learning much less but they have some very advanced "pre-baked" capabilities.
Most of what I've seen is that they have fairly amazing learning ability when it comes to problem solving, and also when it comes to applying observations of other octopi solving problems (e.g., an octopus can figure out how to work mechanical things that pose barriers to food, and one octopus can watch another octopus work such an mechanism once to learn how to do it themselves.)