Source even though you won't click into it: http://www.wired.co.uk/news/archive/2013-06/11/bitcoin-prism
There are many Gift Cards that act like Debit cards online that do not require a SSN, address or any identification to purchase. I buy them at my local grocery store all the time. Fully anonymous cards. Cash is fully anonymous if you're dealing with someone in person. You can take cash and hand it to anyone without them knowing anything about you.
I've used gift cards to buy "questionable" items completely anonymously. I give a fake name and used a university open address department mail drop. I have a friend thats working on his doctorate in Political Science and distributes the mail. I just have him set aside any packages that come for Tom Jones. That's only one way to do it. In my neighborhood, the postman sits packages that are to big for the multi-box on your doorstep. I just ship it to my neighbors house and watch the daily mail delivery. Everyone is at work and I'm retired so I just walk over and pick it up.