My favorite Mexican place in the world is very close to where I grew up. It’s called Tito’s Tacos. They always give out fifty cent pieces in their change and have for decades. It’s a tradition. 99% of the fifty cent pieces in Los Angeles have been though that place, probably multiple times.
I’m sorry, but I read that as “Taco’s Titties.” It must be late. 
Generally, we have the 1, 5, 10, and 25 cent bins, with one extra bin for any odd coins in the till. Then we have the slots (long bins) for 1, 5, 10, and 20 dollar bills. Again, there’s an extra slot sometimes for the checks or 50 dollar bills, or odd bills or coupons. Sometimes that extra slot is really booby trapped with a bundle of ones…if the cashier lifts that bundle, a silent alarm goes off. Lifting that bundle means that the cashier is being robbed.
In grocery and big box and department stores, it’s common to slip checks and any bill over $20 under the cash drawer. Back in the days of carbon copy charge receipts, we’d put them under the drawer too. The thing is, we’d almost never have to use any bill larger than a twenty to make change, so we’d put it out of sight. This also would help prevent a cashier from accidentally giving out a fifty when a lower bill was called for.
It’s too bad about the Kennedy half-dollars. I think they’re one of the finest-looking U.S. coins.
I noticed that, too, back when my parents were living there. (My stepfather was in the U.S. Army stationed there.)
On one occasion, my stepfather bought some furniture from a local furniture store. The store did not accept credit cards, and didn’t have any sort of credit terms available. Instead, they suggested that my stepfather take out a loan from a local bank. He did just that.
When he went into the bank, and after signing the loan documents, the loan officer proceeded to reach into his jacket pocket, take out a envelope, and count out five (5) one-thousand-Deutschmark notes, which was the amount of the loan. My stepfather then paid for the furniture with the cash.
Down here in the South, there are several places I have been to where the $50 bill is treated as if it had plague germs attached.
Why?
Consider that even now in the second decade of the 21st century, there are still southerners who consider Grant (whose portrait graces the obverse of the $50) to be an evil man deserving of no respect.
Hard to believe? Yes.
Irrational? Yes.
True? Yes.
There are times when I wish I had been born somewhere else.
So Civil War commemorative quarters with Sherman or Benjamin Butler wouldn’t be very popular?
Large purchases in cash are typical in Thailand, even for houses – IIRC, when we sold our previous condo, we were paid in cash – although bank transfers are becoming increasingly more common. Checking accounts are rare, almost unheard of, and credit-card limits make it impossible to use cards for larger purchases. The largest note here is 1000 baht, equivalent today to US$33.
Of course, this is made easier in Canada by the fact that twenties are mostly green with highlights of yellow and purple, and fifties are salmon-red colored. 
Are the colours on the newest US bills helpful?
Sure, but there are still some old bills of each denomination in circulation. Old (green-and-black) $20s are fairly rare, but those are probably the most commonly circultated denomination besides the $1. There are still numerous old $5s, $10s, and $50s going around. Especially $50s which don’t circulate much, so they don’t wear out quickly. We still don’t have the new $100 issued yet. Not sure why, since they’ve been promising it for a couple years now.
Don’t work. They only work on the cheapest paper. A counterfeiter doesn’t need to do anything fancy – just basically not use newspaper. If you want to prove it to your boss, just take a bill and some regular paper and mark them both with a pen. Notice that the colors are the same.
The best way is to make sure to look at the strip and make sure that the words say the correct denomination. Or, make sure that the watermark is the correct dead person. Be careful, because some counterfeiters are bleaching $5 bills and overprinting them with $20 and $100 images. They have strips and watermarks, so they look OK on cursory inspection. You have to make sure that the strip and watermarks match the correct denomination.
I don’t find the colors particularly helpful. I’m not used to associating a certain color with a certain denomination, and I still kind of think that the colors look WRONG, like it’s play money, not real money. That’s just my experience, though, and other people’s MMV.
Maybe because he was the last Democratic president with facial hair to be elected.
Following that line of reasoning, they ought to have put William Henry Harrison on fractional currency.
Don’t forget the trillion dollar bill that Fidel Castro stole from Mr Burns.
It has Harry Truman on the front, but what exactly is on the back? (I presume the frame is reversed because of the backwards “one trillion”)
Truman on the front, and just the words “One Trillion” on the back, it looks like.
Remembering back to jobs where I worked a register, my experience agrees with Lynn’s, including the general SOP of putting higher-denomination bills under the cash drawer.
For me, not in the least. The colors are so bland and washed out you hardly notice them. I feel that their main function is to make our currency look more depressing. 
And tell strippers to start wearing catchers masks and giant diapers. Dollar coins would absolutely ruin strip clubs. Not that everyone cares, but still.
I am reminded of a strip joint in Texas way back when. Some old codger – no, not me, I was still young then – got up and tried to put a quarter in the G-string of the girl on stage. To which she replied: “I’m not a goddamn slot machine!”