This paper begins by teasing out the nature of social capital and its particular and current relevance to adult learning policy and practice in Australia. The paper identifies a number of benefits and significant problems with social capital as an organising construct for adult learning research and policy in Australia. Some connections are made between social capital and lifelong learning, and important distinctions are drawn between "bonding" and "bridging" social capital. I draw on my experiences and insights over the past seven years using network diagrams as a research tool. Network diagrams are identified as a useful tool for charting relationships between learning organisations and individuals. The paper suggests ways of using the network relationships in these diagrams as a proxy for social capital in a range of formal and informal settings in which adult learning occurs in Australia. Network diagrams are seen to have particular utility in situations where communities and organisations become too small for surveys, where relationships become complex and ambiguous as well as in rural and remote communities where distance and spatial relationships affect access to learning.