Given that the communities which are most vulnerable to HIV often have little control over their own lives and their health-related behaviour, HIV prevention policies increasingly recommend that HIV prevention projects work to build relationships with powerful external groups (i.e., build "bridging social capital"). To aid conceptualisation of how community organisations may build such social capital, this paper outlines a typology of strategies for influencing local stakeholders. We present a study of two successful Indian sex workers' organisations, VAMP and DMSC, focusing on how the organisations have influenced three groups of stakeholders, namely police, politicians and local social organisations. Interviews with project employees (45), with representatives of the three groups of stakeholders (12) and fieldwork diaries recording 6 months of observation in each site provide the data. Three approaches emerged. "Persuading" refers to the practice of holding information-giving meetings with stakeholders and requesting their support. It appears to build "weak social ties". "Protesting" entails a collective confrontation with stakeholders, and appears to be useful when the stakeholder has a public image to protect that would be tarnished by protest, and when the protestors can stake a legitimate claim that their rights are being denied. In "exchanging favours", the sex workers' organisations find creative ways to position themselves as offering valued resources to their stakeholders (such as useful information on criminal activities for the police, a stage and audience for politicians or a celebration for local social organisations) as incentives for their support. In conclusion, we discuss the strengths and weaknesses of each approach, the implications for social capital theorising and implications for community HIV prevention.