Through my work at the Digital Arts Division at the Wits School of Arts we have a loose organisation of people interested in art and technology, this was formed into the Hacksaw Art and Technology Group, but also encompasses the Upgrade! International Johannesburg Node.
See some of out projects on the Digital Arts Division blog @Joburg.
Members of the group get together to share skills and resources, we regularly run workshops in different tech art development environments: Arduino (Daniel Hirshman 2010), Max5 (Andrew Spitz 2010 & 2011).