I think Ivan posted that great link about crows using tools. Maybe he still has it.
I have a collection of favorite African Grey links that you might like:
Most people probably have heard of Alex, the most famous of the African Greys. Alex has a vocabulary of around 100 words but seems to be able to put them together meaningfully. I saw a TV interview with Alex and his trainer, Irene Pepperberg several years ago, and I was blown away when Alex said clearly, "I want go shoulder". Here's an article about Alex:
http://www.123compute.net/dreaming/knocking/alex.html
Excerpt: "Parrots, of course, are famous mimics, and some parrots have bigger vocabularies than Alex. But no parrot, says Dr. Pepperberg, has been able to perform tasks as complex as Alex can. And she believes that when Alex vocalizes, he is expressing the results of his thoughts, not mere mimicry. For instance, when she asks Alex what color corn is, he answers yellow, even though there is no corn around. This means, she says, he has an abstract concept of what the words "color," "corn" and "yellow" mean. He has not simply memorized them, but can apply them to different objects."
There is more info about Irene Pepperberg's research with Alex and other African Greys at The Alex Foundation:
http://www.alexfoundation.org/
N'kisi is another impressive African grey.
http://news.bbc.co.uk/2/hi/science/nature/3430481.stm
"The bird, a captive African grey called N'kisi, has a vocabulary of 950 words, and shows signs of a sense of humour. He invents his own words and phrases if he is confronted with novel ideas with which his existing repertoire cannot cope - just as a human child would do."
Here's an article about an loquacious African Grey named Einstein. Einstein is interesting to me just because he/she seems to take pleasure in mimicking.
http://www.cbsnews.com/stories/2005/08/10/earlyshow/living/petplanet/main769849.shtml
And I
love this video of Einstein:
http://www.break.com/index/petstar.html