I agree with you (writing from South Africa), that the media plays an extremely positive role in this regard. Crucially however support efforts would need to focus on that media which is independent of state intervention - a thing easier said than done in many cases, but no reason not to try.
Particularly worth considering are media that allow for two-way communication, esp cell phones. They're a fantastic tool for social action as they allow easy, direct feedback and a degree of citizen anonymity that makes reporting corruption and crime somewhat more likely.
An example of a local initiative seeing some success is an anonymous tip-off sms line through which citizens can alert the police to crimes that are being planned by other members of their communities. It could equally be an effective means of drumming up protest against corruption.