Profiting from the downward trend of the economy
Good, takes a bit of timing, skill, and some luck, and again, not passive per se (but quite lucrative if you have large sums of money)
Online mortgage investments/marketing
Tax Liens I'm really interested in this one - apparently very safe, highly profitable, and long term (so once you set it up, good-as-passive)
Land Banking a very interesting investment strategy involving all sorts of neat stuff. Definitely looking into that more.
Debt Purchasing very, very cool stuff. Gotta do your homework (read the book) but yeah, cool!
aaaaand... Filling out surveys
Not passive, apparently lucrative. Meh. I dunno. Its been around a long time, but I just don't see the profit in it.
Sensei Ono, Shinka Martial Arts
How could you best encourage a blogger to blog?