It's pretty simple. I generated a bunch of public/private keypairs. I kept the private keys offline and I hand out public addresses when people add a message.
Which part is generating the keypairs? Is it bitcoin specific?
I'm curious how it's done. I'm thinking to code up something where people can have a small amount of bitcoins donated to every URL they visit. If it ever caught one if could be a way to fund content instead of ads.
Then I poll blockchain.info for payments.