Sudoku: Number puzzles find fans across the country

"I've got two words for you: eraser pen."

That's the advice of international flight attendant Debbie Grant of Annapolis for anyone looking to join in on the latest puzzle craze, sudoku.

Ms. Grant got hooked during a trip to London when she spotted one of the number puzzles in a newspaper. They became a pleasant - and quite challenging - diversion during downtime on long flights.

"Oh my God, it's so much fun!" she said last week. "If you get one number in place, then you might get another one. I'm trying to get better at it, but it changes every time."

Ms. Grant said working on the puzzles makes time fly. In fact,...