The portal for the Interaction Design Association.
“The Interaction Design Association (IxDA) is a member-supported organization dedicated to the discipline of interaction design. Since its launch in 2003, IxDA has grown into a global network of more than 100,000 individuals and over 200 local groups, focusing on interaction design issues for the practitioner, no matter their level of experience.”
There are a large number of local IXDA groups around the world, including London.