First point, In the movie I, Robot, there were two types of machines. Your everyday robots, the NS-5s, who while they would probably pass the Turing Test, wouldn't be considered AI in the sense of a personality. The second type, those that had a personality, thoughts, dreams etc. was represented by Sunni and Viki. Secondly, in his novel Sunstorm, Arthur C. Clarke suggests search engines as one of the more likely sources of an AI.
Two recent developments in search engines have been Wolfram Alpha, and Google Squared. According to the Google Squared FAQ, it improves further results from people editing their result squares, much in the same way as the spell check on your phone on a much larger scale.
So what would happen if you took google squared, combine it with the ability to get results from questions (like Ask.com) , and left it running for a few years to gather data, like 20Q. Then you add in a few questions people ask each other, but don't search, like "How is the weather?". It wouldn't be Sunni, but it might stand a good chance of passing the turing test, like the NS-5s in I, Robot.