I found a few articles from back in 2007-2008 where one company announced they'd be demonstrating a round LCD at a trade show for use in cars, but I haven't been able to find any other information or any suppliers.
The reason I ask is there's a project I'm thinking about doing at some point in the future which requires a round display around 3-4" in diameter mounted inside a cylinder. I could use a smaller display if I could magnify it somehow, but I suspect if I stuck a magnifying glass in front of a display I would have problems with the display being distorted or unfocused and visible only from directly in front.