The Guardian talkboards has a thread at the minute called 'The thread about stuff you see on films that doesn't really happen.'
It's a long thread, but if you persevere you'll come across some really interesting stuff on the middle ages, particularly in the posts of someone called 'Oddsock.' Particularly useful for my fellow writers, but interesting for its own sake. I don't know who Oddsock is, but he/she certainly knows his/her stuff
(Edit) Oh, wonderful! Oddsock has added a brilliant post on medieval outlaws. Folks, you have to read this stuff.. It's ace.