Firstly, this only works if you have a permanent Internet connection, e.g. ADSL, DSL, cable. You install software on your machine to map a ARDDS area on your drive to a share and set the size for the file.
The first time you run the program, your computer registers itself with the ARDDS server. When
you put data into your ARDDS share your computer contacts the ARDDS server and is told a list of other ARDDS users to send the data onto. Your computer encrypts the data and send it on. Your data is then safely stored on not only your machine but on four other machines spread around the Internet.
The price you pay for this service is that the software opens up your hard drive and internet connection to store ten times the data you set aside for yourself. One is for your data, four for the encrypted files of other users and five for data capacity that the service provider sells on to make their money and keep this service free for users.
This space could be sold to companies who want a greater sercurity than five copies or to FTP and web sites who want to divert requests to keep their bandwidth bills down.
Disaggregation: splitting the data in to little bundles, encrypting them and spreading them far and wide. It was in my head when I wrote this but didn't make it onto the page (honest). To avoid too much complexity you could divide your data into blocks, each blocked striped into five units and each stripe mirrored five times. The striping would have the advantage of reducing the bandwidth hit on the users. It was is not intended as a security feature as the data is still in one encrypted lump on the users hard drive which is accessable with the right password over the Internet.
Geography: I hadn't considered this but upon registration you could get users to input a rough location and the mirroring could take this into account.
Users opting out: The reason why I picked a high number for the the mirror is to provide a large amount of safety without worrying too quickly about users disappearing. I visualised the users' computers checking in at least daily to say that they were still there (and giving their IP address in case they have a connection with a dynamic IP address). As an example, if a user's drive is not accessible for a week the fragments of the shares that are missored there would be mirrored somewhere else. After a month the mirrors of that user's data would be removed. After siz months their account would be deleted. (something like that)
Pornography: You get absolutely no visibility of the data thta is stored in the ARDDS section of your hard drive. It's an encrypted binary block. You can't even see filenames. Pornography, blackmail or just someone's diary, archived email and family photos. You'd never know.
Remote access: Forgot to add this earlier. Since the data is stored on Internet accessable drives, you can get to your data from anywhere. A password would be needed to access the data and a further password to decrypt it.