Ancestry.co.uk have opened their First World War military files for free access this week - you just need to put in a name and email address to open a free account and then you can access their archives. I've been looking for information for my Dad and I've found my Grandad's tank corps papers and also pages and pages of information on my Great-Uncle who was killed not long after he joined up -
http://www.ancestry.co.uk/ukmilitary_offer
History