Its true that there isn't an intrinsic orientation to the board in Othello, (or Tic Tac Toe), however, that shouldn't be an immediate concern for designing the board structure. A 2D array would probably be sufficient for all data-keeping purposes, and a 3-d array if you wish to be able to review the game.

The no-orientation aspect of the game will play a huge role in the construction of any strategic algorithms(the fun part of this project), as you do not want to waste time reading out future sequences which are equivalent due to the geometry.

One way to avoid this would be to create equvalence classes of positions on the board. For example you could store center, side and corner data for a tic tac toe game, as opposed to storing x-y coordinates. Think graph theory.

This is a little vauge, let me know if you'd like some elaboartion. -muoyo