#bbcsms: Please join us at the BBC Social Media Summit

We live in a time when the words 'Facebook' or 'Twitter' can propel a news story up a programme's running order, or onto a front page, often for no good reason.

But behind the hype - and let's admit there's a fair amount of that around - real, structural change is taking place in personal and public communications. In particular, there's a new and shifting border between the private and the public, mediated by social media businesses.

For journalists, social media is producing change on several fronts. Where initially social media was seen as a way to tap into new sources of information, today it is at the centre of new kinds of relationship between journalists and audiences in which gathering information is just one facet.

The BBC's Social Media Summit is an ambitious attempt to see the big picture - by bringing together top names in the field and encouraging debate, both at our two-day London conference and with a global conversation on our website that will continue, we hope, long after everyone's gone home.

I would like to invite you to join us, online or in person, at the sessions and to contribute your thoughts by commenting. We'll be trying to pull the whole subject together at a final session in which we will include the best online comments - so please be assured that your thoughts will be part of the debate.

Matthew Eltringham is Editor of the BBC College of Journalism Events and Website.

Details of the Summit and confirmed guests here; full list of attendees here.