When I was a kid, I put all of my money in a simple jar, all $5.80 worth. Kids today now have their own private ATM machines to manage their allowances finances! The Zillions Touchscreen ATM Bank is cool new miniature version of an ATM for kids!
They can deposit and withdraw real coins and currency into the machine and it will give them up-to-date account information (up to $999.99) right on its backlit touchscreen screen. Their money is relatively secure too, because it comes with its own ATM card and a security pin number can be set as well. It's really the perfect thing to help teach kids money management and savings, plus it's just kinda high-tech cool.
I really wish they made a larger, professional version just for adults, because I still save all of my loose change in a jar.