The American Association of Geographers holds annual meetings, usually in late March/early April in locations across America. Each year, this is a big event, drawing as many as 7,000 participants. This event is open to anyone with an interest in geography and/or associated disciplines and registration for the event is always available on the AAG website. For further information, please see: http://www.aag.org/cs/annualmeeting
In the UK, a similar annual event is hosted by the Royal Geographical Society in concert with the Institute of British Geographers. It typically attracts around 1600 delegates from around the world and takes place in August/September each year. Locations for past annual meetings have been London, Edinburgh, Manchester, Glasgow, Belfast, Plymouth, Sussex and Leicester. For further information, please see the Annual Meeting pages of the RGS website.