Neville Hobson pointed today to CIPR (the Chartered Institute of Public Relation - UK)
CIPR has just launched a 'social media paper' and opens the consultation and discussions on the matter (open until Dec 31, 2006).
If you live in the UK, they invite you to partizipate and if not ...
you might learn a lot from reading this thoughtful and sometimes pr mind provoking consultation paper for developing your own guidelines.
Read more about it, at Tony Bradley (he is CIPR's president) Blog PR Voice