Feel free to add pointers to events in comments....
May 23-25, 2006 WinHEC (Windows hardware Engineering Conference, Seattle
May 25-26, 2006, Apply Serious Games, Society of Chemical Industry, London SW1
May 30-June 3, 2006, USENIX 06 Annual Technical Conference, Boston Marriott, Boston
May 31-June 2, 2006, Search Engine Strategies, Business Design Centre, London
June 5-6, 2006, International Serious Games Event (ISGE) for developers and publishers, International Convention Centre, Birmingham, UK. (Supported by UK Trade and Investment, Coventry University and Advantage West Midlands.)
June 6, 2006, Content 2.0, RSA, John Adam St, London
June 13-14, 2006, Where 2.0 Conference 2006, San Jose, California
July 11-12, 2006, Develop Game Developers Conference, Brighton.
July 24-28, 2006, O'Reilly Open Source Convention 2006, Portland, Oregon
July 28-29, 2006, BlogHer Conference '06, Hyatt San Jose, San Jose, California
July 30-August 3, 2006, Siggraph 2006: The 33rd International Conference on Computer Graphics and Interactive Techniques, Boston Convention & Exhibition Center, Boston, Massachusetts
September 18-21, 2006, O'Reilly European Open Source Convention 2006, Brussels, Belgium