Stilly -

Possibly some help for US folk at least. This article appeared in a fairly recent AARP mag. This won't stop the worst of them, like the ones that are working off your mortgage, perhaps; but it might get to some of the bulk types.

I didn't find a link direct to the article, so the whole thing was:

Q. We are being inundated by unsolicited credit card offers—220 applications in the last few months alone. We requested in writing that our names be taken off all mailing lists, but to no avail. What can we do to stop the flood?

A. First write to the offending companies and say you want to be taken off all mailing lists.
Then call (888) 5-OPTOUT—or (888) 567-8688—toll free. You will reach, with just one call, the three major consumer reporting companies. Tell them to stop giving your information to companies that want to send you pre-approved credit offers. You are required to give your Social Security number, name and address.
You can also have your name removed from many national direct mail lists by writing to the Mail Preference Service, Direct Marketing Association, P.O. Box 643, Carmel, NY 10512. Or, for a $5 fee, you can do this online at www.dmaconsumers.org/consum erassistance.html.
The stream of offers should slow within 30 to 90 days of your request. For more information, go to www.aarp org and search "Unwanted Mail."

John