I'm in Phnom Penh for a meeting of sex worker advocacy groups from around the globe. Tactical Tech is doing work on helping these groups exchange information for both their global advocacy work but also for local advocacy. We just completed a survey of organizations and one of the most striking examples of use of media for an advocacy strategy (and there's actually quite a few) is from a group in Taipei calle COSWAS that have produced an excellent video about the plight of Sex Workers. I'll warn you that these video's are in Taiwanese but you don't really need to understand the language to get whats going on.
Take a look at them at: http://www.youtube.com/watch?v=eBAZ4RxPxDM
and http://www.youtube.com/watch?v=QKndBqiQLho