But who cashes out their whole paycheck, besides a teen making minimum wage working part time? Cash has a great "equivalent", by feeling its disappearing mass. When it's gone, you're done spending. Not much more simple than that.

It's not like every tiny cash purchase doesn't have a corresponding receipt, cash can show spending history just as well as a bank statement. The potential dangers with debit cards is the same with check writing--the delay in clearing and the order of debits. That's something cash will always trump.

I've noticed my area is offering more discounts for cash gas purchases, and some restaurants not accepting credit cards at all. But they never refuse cash.