Yep, a dividend paying, mutually owned whole life insurance policy:
Infinite banking refers to a process by which an individual becomes his or her own banker. The infinite banking concept was created by Nelson Nash. In his book, “Becoming Your Own Banker,” Nash talks about the use of whole life insurance policies that distribute dividends and how owning such policies allows individuals to dictate the cash flow in their lives by borrowing against/from themselves instead of depending on banks or lenders for loans.
If you borrow money from the policy, it continues to make compounding interest on the whole amount in the policy as opposed to interest on the amount that's left after your withdrawal. There's also no tax penalty for withdrawing the money. You pay it back with interest, but guess who's getting the interest? You are.
From what I've read, banks invest tons of their money in this type of thing.
I'm just at the cusp of being able to invest at a decent rate age-wise, but I plan to invest in policies for all my kids since it will be very cheap at their age. By the time they're at the age of maturity they should have nice nest eggs in the form of insurance policies that they can withdraw money from as opposed to going to beg a bank for money and paying the bank that interest. I figure this is the cornerstone of generational wealth.