For our professional computer geeks, educators, programmers, tech journalists, content developers, etc etc, the Virtual Worlds Expo is a go for LA (California, USA) in September.
"Virtual Worlds Expo is dedicated to helping businesses harness the power of virtual worlds to engage with their customers, partners and employees. Conference agenda will include consumer worlds, enterprise worlds, investment and strategy, education uses of virtual worlds, virtual law and visionary/future development" These guys pick up heavy hitter sponsors like Electric Sheep Company, IBM, SL Grid, Virtual MTV, Cisco, etc.
Interestingly, if you sign up now, you same some MAJOR Linden... er... um... dollars. As in US dollars!