If you think it doesn't matter where you keep your savings, think again. There are several options for depositing your cash, each with different perks and limitations. If you choose a money market account (MMA), you'll have easy access to your money, but the interest rate on the account could drop at any time. With Treasury bills (AKA T-bills), the opposite is true: You can't access your money as easily, but your rate of return is guaranteed as long as you leave your money on deposit until the maturity da ...