This is a plug for the Friends of The National Archives, these good folk work hard behind the scenes at TNA, Kew indexing and raising money for various projects. You don’t have to visit the archives to help with projects, arrangements can be made for material to be sent to you for indexing.

Standard membership costs  £15 per year and for that you get a journal three times a year and a 20% discount on purchases made at The National Archives bookshop.

http://www.nationalarchives.gov.uk/friends/friends.htm