letterboxing is very good. i met some people that did it travelling. they got a stamp or sticker or something, and then exchanged an object and took it to the next box.
I was looking at Traid and they do things with schools etc, we can get one of there clothes banks put outside school and they are big on events with the community, but I don't know how we could turn it into self-promotion if we work with a charity, when surely we would be focused on promoting the charity itself?
I like the idea of a treasure hunt but maybe create an exchange of work? not just found objects but something we have made?

We can fax agencies maps and our symbol as we originally intended, I think we would have to get going with that soon though to build up interest.

It would also be something we could do on the southbank, if we want to attract the public then we could make it a weekend activity, publicise it through the hayward and the southbank centre. We would be attracting people from the arts sector but not specifically design agencies.

Rachx