What's the cheapest possible way (including the hardware) to stream one to many, live, from a portable device, in an area that probably has public WiFi? Note this really needs a shoulder or helmet mounted webcam. It should be capable of 6-12 hours running on a battery and allow battery swapping to extend that.
I'm thinking Google+ Hangout + webcam + notebook in a backpack. I could be wrong, but I don't think any of the clever phones can use a separate cam.46-71 Trinity Rd, Ware, Hertfordshire SG12 7
Another one I'd like to try some time is a throwaway phone hooked up to a loudhailer and a big sign on my back saying "Call this number and have your say".
This also reminds me of a conference a long time ago. A well known person couldn't be there so somebody carried a laptop round open in front of them with a webcam and a Skype session so the celebrity could be there virtually and interact with individuals who got within camera/speaker range.