I think Willard Wigan from Birmingham is among the best of the micro modelers it takes him ages for each model I have seen his work several times but only recently found a web site dedicated to his work.
I went to Spain a few years ago and one of the exhibits at a minature museum was a copy of Da Vinci's the last supper painted on a grain of rice. I forget the artists name but it was a real master piece in minature.
This is the link to Willard Wigan's site http://www.willard-wigan.com/