1. Operate a transaction server (running Open Transactions) in return for transaction fees. These can be earned anonymously, and thus the server has the option to run anonymously (on Tor or I2P, etc.)
2. Operate an anonymous remailer, SERVICES PAID FOR IN DIGITAL CASH. Run it on Tor if you want.
3. Operate a Nym server, services paid for in digital cash.
4. Operate a Tor outproxy, services paid for in digital cash. Finally these sorts of services can be offered for profit, instead of relying on hobbyists and enthusiasts!
5. Integrated with an anonymous network, Open Transactions solves problems of resource allocation. College kids will leave their computers running all day while they're in class, so that anonymous file-sharing can occur through their computer while they're away (collecting digital cash postage in return.) When they get home, the postage is theirs to keep -- or they can use it to pay for their own downloads. Voila! Anonymous networks can now be drastically sped-up through the anonymous contribution of resources. If you don't want to contribute computing resources, that's fine: just pay for those resources with anonymous digital cash instead, and the network will provide you those resources from someone else. Relevant: http://cap-lore.com/Economics/DSR/SilkSec.html
6. The above (5) is true for MESH NETWORKS as well. Imagine Mesh routers popping up like mushrooms, the same way that ATM machines pop up today. Instead of paying your ISP for network resources (with a credit card), rather, pay your PEERS for network resources using digital cash (backed in Bitcoin...)
7. Issue a digital gold-based currency (whether or not you actually run the server itself, which could be run by another entity) and earn transaction fees (if you operate it yourself) or issuer fees from the server operator (if someone else operates it.) These fees can be earned anonymously and untraceably. (Make sure to follow the laws in your jurisdiction.)
8. If you already run businesses that value privacy, such as porn or gaming, issue a currency so that you can offer anonymity to your customers, thus making you more competitive in your own market.
9. Or partner with someone else who issues the currency, in order to keep the two businesses entirely separate.
10. Write a Wallet software that is also a file-sharing client, that allows users to pay for faster anonymous resources using digital postage. The wallet also contains an anonymous network node internally, so it has the capability to collect postage as well. If the Wallet software is unregistered, then the postage is sent home to the software company. Also, expired cash reverts to the software company. But once the wallet is registered (with a payment to the software company) then postage is retained by the user and expiring cash is exchanged for the user. The wallet software itself can be distributed for free. This constitutes a great example for the next generation of file-sharing integrated with digital cash.
11. Darknet hosting. Tahoe might be adaptable to this: http://tahoe-lafs.org/trac/tahoe-lafs
- The software could be licensed to a legitimate bank. In fact, this has actually happened once before, if you Google the history of DigiCash and Mark Twain bank. (I think the software has better potential uses.)
- The software could be used for horse racing or concert tickets.
- It could be used for payments on toll roads, since many countries have strict privacy laws.
- It could be used for video games. StarCraft II could use this software to track and control their star credits. Warcraft 2 could use this software to track and secure their warcraft gold. Etc.
- Anonymous donations and tips online.
- Secure, online transactions for community currencies.
- Secure system for issuing other online currencies such as Bitcoin. (Enables you to write cheques in Bitcoins, withdraw chaumian cash in Bitcoins, get cashier's cheques in Bitcoins, etc.)
- Secure and private financial transactions made possible even in countries with oppressive financial laws or unstable currencies...