Guardian Unlimited launches Sudoku puzzle league: "Guardian Unlimited and Solid State have announced the launch of a new Sudoku league which lets players solve puzzles on their mobile phones and submit scores to compete head-to-head in the online league."

Vague professional envy here :) Puzzler Sudoku has an online league but it's not as exposed as it should be (yet).

I've not tried the Guardian service myself, but it looks like they're doing some sensible stuff around leagues and pricing... Good to hear that it's "mobile as part of our overall strategy, rather than a distinct mobile strategy."