Now that you've mentioned it, I will start looking for one.

What I've been doing is feeding my Sudoku habit, which I find more satisfying than crossword puzzles. I mention this because WebSudoku lets you enter more than one number in a cell in case you're not certain which of two (or three or four) is the right one. Most of the mechanics of WebSudoku are in Javascript, and this may account for how well it works on the 770.

Of course, you do have to go back online to check your answers . . .