i saw this
http://money.cnn.com/2013/05/02/tech.../bitcoin-porn/ which has lots of interesting links in it.
basically you can put a message in the header of coins, and once that gets out in the blockchain it will be there forever. someone else has stored a few MB of wikileaks stuff in the blockchain, so for as long as people use bitcoins the data will be out there.
this is a potentially revolutionary type of thing imo. if we can store complete total information of the world in our money, it would make everyone have to keep all information we have in circulation. information would be directly tied to spending value. the only way to counter this would be if the people would didn't want this information out would have to mine bitcoins at a higher rate and put bad information in them. but putting all knowledge into bitcoin headers would tie their value to information intrinsically. and money is just a form of information anyway right? but this would be more powerful because it would be complete information
for example, could we stuff all of wikipedia into the blockchain? once storage is even more powerful this doesn't seem hard. i think i read that once all bitcoins are mined the blockchain would take up about 120 TB, so if people were happy to carry that around in their USB wallet (or w/e) then we could have an even bigger blockchain.
i dont know too much about this but i was theorizing about it and needed to type it out before i forgot