Findmypast.com - Family tree research using births, marriage and death indexes. - http://www.findmypast.com/
British Origins - Subscription based access to data provided by societies and libraries including primary sources, abstracts and index databases. Lists sources and fees payable. - http://www.britishorigins.com/
UK BDM Exchange - Subscription based forum for swapping unwanted birth, marriage and death certificates. - http://www.ukbdm.org.uk/
UK Ancestors - Facility to publish a family tree and view pages created by other users. - http://ukancestors.org.uk/