Its an interesting thought to be able to see a business's public transactions and tell what other people are buying. If a company used a singular deposit address and signed all transactions with a product ID number. You could tell what products are popular.
I like the idea of having a way for business to keep a public ledger for tax purposes too. every transaction listed with product and price and time of sale.
I signed a few here.
http://blockchain.info/address/14C99on9MmBFtenge5tV9djZBDYon1okw6 I'm just not sure if this is built into the bitcoin client or just a blockchain.info thing allowing the public notes.
Im reading though those other articles now. thanks