you would probably NOT be amazed to hear how much http://www.patientopinion.org.uk/ has really changed the priorities of local NHS trusts, and how many have set targets around media (inc social media) coverage of their outfits. it's brilliant. 3 votes from me
I've done this, very successfully in East Leeds. Would it bore the pants of people if I talked about the potential for QR codes [http://en.wikipedia.org/wiki/QR_Code] on laminated bits of card that hyperlink real places to information? Only really viable for smartphone users in ready mapped areas though.
4square for community orgs anyone?