Sudoku, anyone?

[igotrhythm]

By now, you're probably aware that a new kind of puzzle has taken hold in the minds of American citizens...the Sudoku or "single number" puzzle. It's basically a logic problem...you're given a 9x9 grid divided into nine 3x3 grids and some numbers scattered throughout the grid. Your job is to fill in the rest of the grid so that each row, each column and each 3x3 box contains the numbers 1 through 9.

I've started to dabble in this sort of thing, and while I sheepishly admit that the Medium level on the 3D Sudoku site (go to www.2flashgames.com and click on "Puzzle Games") tends to leave me stymied, there's a similar program on Miniclip, only the ones there are MUCH easier. I once knocked off one of their "hard" puzzles in under 20 minutes, doing all the figuring in my head.

But getting to the real point of this topic: do you do these kinds of problems, and if so, how good do you think you are?