Business Network International
http://www.bni.co.za  
BNI (Business Network International) is a business and professional networking organization. Its chapter members meet weekly (usually over breakfast) with the objective of generating word of mouth referrals among members in a structured and supportive environment. There are chapters in Cape Town, Johannesburg, Durban, Pretoria, Pietermaritzburg, Mpumalanga -Lowveld, KZN South, Garden Route, West Rand, Ekurhuleni, Nelson Mandela Bay, East London, West Vaal and Highveld.

Businesswomen's Association of South Africa - BWASA
http://www.bwasa.co.za
The BWA was formed from the merger of the Executive Women's Club, the National Association of Women Business Owners and Professional Women's Leadership Development Organization. It is a voluntary, non-profit organization. Its members include entrepreneurs, professionals and senior decision makers; membership is open to both men and women. The Businesswomen's Association is the largest and most prominent association of business and professional women in South Africa; it is the voice of women in business. Through strategic partnerships with sponsors, non-profit organizations, leading companies, business schools and international associations, it provides ongoing opportunities to advance the interests of women in business.

Business Women's Association of South Africa
Post Office Box 2562
Saxonwold 2132
Gauteng
Tel: +27 (11) 648-0356
Fax: +27 (11) 648-0357
Email: gauteng@bwasa.co.za  

COSATU – Congress of South African Trade Unions
http://www.cosatu.org.za
COSATU was established in 1985 and is the largest of the country's three main labor federations. It is a partner in the Tripartite Alliance, together with the South African Communist Party and African National Congress, and has a combined membership of more than two million workers grouped into 21 affiliated trade unions.

Congress of South African Trade Unions
Post Office Box 1019
Johannesburg 2000
Gauteng
Tel: +27 (11) 339-4911
Fax: +27 (11) 339-5080 / +27 (11) 339-6940
Email: cosatu@sn.apc.org  

This is just a sample of what you'll find in the complete South Africa guide.