Peg Solitaire
(From Wikipedia) Peg Solitaire is a board game for one player involving movement of pegs on a board with holes. The game is known simply as Solitaire in the United Kingdom where the card games are called Patience. It is also referred to as Brainvita (especially in India). Some sets use marbles in a board with indentations.
 Peg Solitaire on the XO
Peg Solitaire was created expecially for the XO by a team of students at the Entertainment Technology Center of Carnegie Mellon University. The team will be developing games for the XO from August to December this year (2007). Visit their website to learn more about the team and about what they are working on. The team would love comments on their game, so please download it and play.