Idea for file hosting and proxy services
When you want to upload an image to embed in a forum post, there are services like imageshack, but because they're free, they limit the number of views. It's a minuscule amount of bandwidth cost, but they can't just give it away for free, there has to be something in it for them. It would be nice to be able to pay for the bandwidth and avoid the limits, but conventional payments are too inconvenient for such a minor thing.
It's worse if you want to upload a file for others to download. There are services like rapidshare, but they require the downloaders to go through extra steps and delays to make them look at advertising or encourage upgrading to a paid subscription, and they limit it to 10 or so downloads.
It would be nice if we made some free PHP code for an image and file hosting service that charges Bitcoins. Anyone with some extra bandwidth quota could throw it on their webserver and run it. Users could finally pay the minor fee to cover bandwidth cost and avoid the limits and hassles. Ideally, it should be MIT license or public domain.
Services like this would be great for anonymous users, who have trouble paying for things.