The closing date for proposals for the Virtual Worlds Best Practices in Education (VWBPE) conference is 15th February 2011. This conference, held mostly in the virtual world, Second Life (the picture shows one of the venues last year), runs for 48 hours 17-19 March 2011. "This grassroots, community-based conference attracts faculty, instructors, trainers, administrators, instructional designers, technical specialists, and members of organizations from around the world. Those who create teaching/learning environments, resources, tools, support services and professional development opportunities internal and external to virtual world environments participate."
Website at http://conf.vwbpe.org/