Now you can download the Othello game for your Nokia N900. It requires the Qt Web Runtime which can be installed at time of writing from Maemo Extras-devel repository as mentioned in Qt WRT forum.

After you have installed the WRT on your N900 then you can point your N900 browser to http://bit.ly/n900-othello-wgt

Happy gaming! Let me know how well the application works on your device and does the computer AI ever beat you :)