Random Recordings of Mental Meanderings

Think about artificial intelligence. How easy would it be to create it? How would one create something like the Issac Asimov positronic brain? Is it possible to create a computer that converses with people? With the advent of Battlestar Galactica on The SciFi Network, the Cylons and such, the idea has crossed my mind many times. With the technology and resources we have today, I would think that it would be rather easy to create a quasi-intelligent, thinking computer.