Daily Kakuro
First, there was Sudoku. Now there is Kakuro, another Japanese number-puzzle game. I haven't tried one yet.
The best sites are http://www.sudokusan.com and http://www.karokusan.com - Proudly destroying productivity since 2005.
Just tried the karokusan. Didn't work.
Looks like the URL is actually http://www.kakurosan.com
Yep. I almost wrote how I thought it was frustrating that, just when I learned how to say 'sudoku' (not 'suduko'), I found the new game that transposed the 'o' and 'u' sounds. Oops.
Another site for free kakuro puzzles is http://syndicate.yoogi.com/cross-sums/
A freeware computer game for download.