Palm and Verizon are now offering a free copy of Astraware's Sudoku. It is available via a ROM update that is available here:
Palm - Support - Verizon Treo 700p Update
More info on sudoku:
Astraware Sudoku for Palm OS - Palm OS
More info on the news of the free game:
Palm Offers Free Sudoku to Verizon 700p Users