Least possible givens in a sudoku...

I was just pottering around the web and was reading some articles about how many numbers you have to have in a sudoku puzzle in order to be able to solve it uniquely.

It turns out that the lowest number is 17, or at least no-one has actually found any puzzles where 16 givens lead to a solution. I'm not entirely certain if there is a proof that you need at least 17 as it seems to vary depending on which site you go to whether there is a valid proof out there or whether it is simply that no-one has ever found one despite all those computers running trying to make one and therefore almost certain that there isn't one out there!

I was looking in some newspapers and books I have here, and I've never seen a puzzle published in a magazine or newspaper with less than 20 givens as far as I am aware... which makes you think that they must be pretty rare.

What's the least number of givens you've ever seen in a sudoku puzzle?

I'm thinking that it might be because the puzzles in newspapers have symmetrical givens... I wonder what the least number you need in order to solve a sudoku puzzle with symmetrical givens is?!