Killer sudoku generator

Does anyone know of a site where you can generate killer sudoku puzzles online?

I know there are many sites where you can play the puzzles online but is there one that has a random generator that you can use to play loads... interested to find out.

Best online killer sudoku I have found so far is at:

[a http://www.saidwhat.co.uk/puzzleclub/killersudoku/killer-sudoku-sample.php [/a]

Though to play the other 100 puzzles you have to pay but I guess you get access to several other puzzles including some interesting other ones like Nurikabe, Fillomino and even Light Up.