Dividends on stocks. I've never had an idea good enough to make an app out of, or build a company around. So instead, I started investing a small amount of my paycheck in to my brokerage account. Buying lots of stock in Dividend Kings[1], I've earned $25 this year, with another $20 through October. It's not a lot, but I'm fully thinking long-term. 1: http://long-term-investments.blogspot.com/2013/02/15-Best-Di...
I guess the other thing I'm doing is finally putting money where my mouth is and putting money into companies I think will succeed in the future.