Selfsufficientish.com

Stop companies from phoning you and if they do they can be charge a big fine. register your number with http://www.tpsonline.org.uk/tps/

Sorry this is UK only not sure about other countries.

You can also set mailing preference from the same site :)

It takes very little time, and will hopefully make for a lot less crap through the post and on the phone.

jema