Tug- Of-War used to be an Olympic Event

That was between 1900-1920. Other past events included power-boating, water skiing, golf, lacrosse, croquet, and polo. These along with orienteering, bowling, billiards, chess, and
many other activities are on the Olympics Recognized Sports List, and can be added to the main Games at anytime.

http://www.olympic.org/uk/sports/recognized/index_uk.asp

http://www.olympic.org/uk/sports/past/index_uk.asp