Here's a fascinating new tool - Churnalism.com. It allows you to enter the text of a press release and find out how much of it was copied and pasted by UK newspapers.
I tried a Friends of the Earth press release about small-scale energy generation and found that around half ended up unaltered in (guess where)...the Guardian.
Or what about a Greenpeace press release about taking the government to court over deep water drilling. Well, roughly three quarters found its way to (a) the Independent (b) The BBC and (c) the Scotsman.