There are a lot of them: rent, deposits in bank, actions and bonds, investment in business etc. We would like to discuss passive income in HYIP. In general, HYIP is passive but not quite so and also very risky. First, HYIPs are constantly closing and money goes to founders pocket. Secondly it is difficult to choose which HYIP can be entrusted. Thirdly you need to constantly watch for dynamic of projects development, and do right decisions - withdraw the deposit, reinvest, make additional deposit... That's why you can't name passive investments in HYIP - passive. If you choose this sphere as a passive income you should head for low and mid yield projects that work for long period and have many positive responses at special forums. Also don't do big deposits (more than $5к) or break it into some small deposits and make deposits from different accounts.