One useful piece of advice:
Don't but pizza with a credit card: SNIP
Course all those terrorists buying their pizzas with cash get away clean.
I've wondered for years how much longer this will be allowed. Cash is still viable. Not as viable as it was 10, or even 5 years ago. I am still able to travel with only cash, buy a pizza with only cash, or other food, still buy groceries without having to produce mein ausweiss (why I stopped shopping at CostCo years back). But it is all getting stickier.
Quite clearly cash has got to go! I'm not sure how tough this would be to sneak past the slumbering electorate. Pretty tough I expect. But the usage level is certainly going down while the percentage of electronic transactions is skyrocketing. We've even had concresscritters suggesting that the transport of $10K !interstate! should be illegal. I think this came up when the most recent international transport rule changes were made. It's getting more wierd every week now. An adjustment in the other direction will come along soon - I hope but doubt.