[Fern]

I would consider banks to be a way to generate appreciable income since they pay interest. But i think what you mean is putting your money into illiquid assets rather than liquid assets. Illiquid means you have to convert it (sell it) to get your money out of it, while liquid assets are still money, you just have to withdraw it fromt the bank or cash in the mutual funds or whatever.

The biggest appreciable item would be real estate. Others would be precious metals such as gold, but like any other appreciable item, they can drop in value as well.