Retrospective format ideas

http://www.mountaingoatsoftware.com/agile/scrum/sprint-retrospective
http://retrospectivewiki.org/index.php?title=Retrospective_Plans
https://www.scrumalliance.org/community/articles/2013/february/iteration-retrospective-activity-turn-the-tables
http://waynedgrant.wordpress.com/2012/04/01/sprint-retrospective-techniques/
http://www.infoq.com/news/2010/12/agile-scrum-retrospectives
http://skycoach.be/2010/06/17/12-retrospective-exercises/