Su Doku

                 
1 8 5 7 3 4 9 2 6
7 9 6 1 2 8 4 3 5
2 3 4 5 9 6 1 7 8
3 1 8 9 4 2 6 5 7
6 5 2 8 1 7 3 4 9
4 7 9 6 5 3 2 8 1
9 4 1 2 8 5 7 6 3
5 2 7 3 6 1 8 9 4
8 6 3 4 7 9 5 1 2

Su Doku.

Apparently invented in Japan, this is the newest puzzle in The (London) Times. Angela and I both like it. Occasionally it is impossible, most of the time its just a little fiddley.