friendsoft has this freeware - SudoX UIQ 3
http://sudox.en.softonic.com/ie/56258a freeware SuDoku and Kakuro program for Symbian UIQ 3 mobile phones

the first version was a little buggy
but this one works well
if you want something w3ith more zing,
try zingles
from zingmagic
it is just a great mobile phone conversion version
one that you can use with stylus
and comes with every conceivable feature you can think of
i know of no other sudoku game on a pda
that's as intutive and well presented as this
dont take my word for it
try it out from
http://www.zingmagic.com/
got this extra bit of information below from
http://www.symbiangear.com/product.html?pid=20066,20081,99931where there is also a free trial download
Zingles (Sudoku) Professional (UIQ3) 2.00F(009)
Zingles, also known as Sudoku,
is a simple yet highly addictive logic puzzle game.
Simply complete the board ensuring that each row, each column and each sub-grid
only contains one instance of each piece – a Zingle piece!
Features:
At the start of a game a number of pieces are placed on the board. These are known as ‘givens’. The remainder of the board contains blank squares for you to complete.
You will need to use all your powers of deductive reasoning to solve the unlimited supply of boards that Zingles can generate. Zingles supports the ability to mark each board square with possible moves to aid in the puzzle solving. Zingles also supports the ‘cross hatch’ marking aid to solving puzzles.
All boards generated are symmetrical and have a single solution making them pure game boards. Zingles also supports the popular game variation whereby the diagonals may only contain one instance of each piece.
Zingles includes a lightning fast puzzle solver able to solve any external puzzle. Simply enter any external puzzle and request the solver to find a solution.
Zingles includes a number of layouts and piece sets. Choose between the traditional number piece sets or for an alternative challenge why not try the letter or coloured gems piece set.
Game features:
Stunning graphics with choice of boards and piece sets.
Choice of layouts including an analysis layout.
Ability to mark squares with possible moves to aid in solving.
Support for the ‘cross hatch’ board solving technique.
Lightning fast solver able to solve any external puzzle.
Check the validity of a board at any stage.
Ability to generate an unlimited number of symmetrical single solution games.
No need to purchase expensive additional game packs
Easy, medium and hard levels of game play.
Allows you to play an unlimited number of games simultaneously
Support for the popular game variation requiring the diagonals to contain unique pieces.
Enter any external puzzle and use the solver to generate a solution.
Supports English, French, German, Spanish and Italian.
Zingles is just one of our large collection of best of breed classic board, card and puzzle games available for a wide range of platforms.