Automatic Micro-payment: The bitcoin killer app!!

I think there are some trading scenarios which traditional cash flow system is unable to provide but bitcoin able to. A micro-payment is a financial transaction involving a very small sum of money and usually one that occurs online. Bitcoin is a peer-to-peer financial system. It is very suitable for these tasks. I thought out several micro-payments scenarios which only can be achieved by bitcoin or other crypto-currencies:

Pay per download:
There are many file-sharing websites. When I want to get a high speed download, however, I often need to become an one-month member. It is vexing, and I only want to download "this file". Bitcoin will be a micropayment system that helping client get one-time high-speed downloading. The website only need to show a bitcoin address or QR code for this download. Or, the website calls the bitcoin-qt API for payment. The amount of money need to be sent are tiny, maybe 0.0002BTC. I think it help file-sharing website increase their revenue. There are a large amount of people unwilling become the member of file-sharing sites, but willing to pay for one-time high-speed downloading.
Pay for priority:
In P2P file sharing networks, there are many leechers, although there are many mechanisms to prevent this problem. I consider that we could incorporate an automatic micropayment agent. If you want to get a file faster, you must pay for it. You can set how many bitcoins you want to pay. The agent will negotiate to other agents to get the higher priority in their downloading queue. It still possible to download without fee and maybe compatible to existing P2P file-sharing software. Users can make benefit by file-sharing that could encourage users increasing their uploading speed and then increasing downloading speed in the P2P network.
Pay per surf:
Fon is a peer-servicing WiFi network. However, it need specific hardware, and it also need to become a member to use their WiFi network. I think there is a way to sell your WiFi service automatically for anyone who has bitcoin. We could modified opneWRT(a popular AP firmware) firmware which is able to show owner's bitcoin address. After payment, openWRT check transaction by viewing blockchain on internet. Finally, AP provides WiFi service to this client. Moreover, we could devise a smartphone App which can find, authenticate and transact automatically. It means smart phone could roam around APs in the city without user's intervention.
Pay per view:
There are forums showing paid content to only paid members. I think it could simplified by using bitcoin. The viewers doesn't need to register, but send bitcoins to specific address for viewing paid content. This idea is also able to be applied to online music, movie, video for one-time viewing.
Pay per authenticate:
Bitcoin will be a cross-platform authenticate method. Because everybody will keep their private key as safe as possible. Website will request a extremely tiny amount of bitcoin from specific address to authenticate user. Also, the semi-automated mechanism can be devised for convenience. And, in discussion forum, there are often many spam messages. The website can place limit on number of free posts. Spam posts will disappear because it is not cost-effective.

I think these scenarios will add value to bitcoin or other crypto-currencies. Is there any similar service already provided? Or anybody has other micro-payment ideas which only can be done by bitcoin? I consider we could promote these ideas. If bitcoin is widely adopted by one-time service, the demand of bitcoin will increase drastically. It is also healthy to bitcoin ecosystem.

Thank you