What Color is your C.F.R.? – PDF version free online – is a nice idea, alas very much a USA thing and not very full (yet) (via Open Law Lab, tweeted by Stéphane Cottin). C.F.R. is apparently the Code of Federal Regulations.

For something more British, The Judicial System of England and Wales: a visitor’s guide is another free downloadable PDF, published by the judiciary, probably of use not only to visitors. In particular, it has a great courts diagram. I especially like the photo on the title page: