How much cash do you carry?

• Not every venue accepts plastic. Examples: toll booths, some cab companies, vending machines.
• You can't always find an ATM.
• Cash makes it easier to split the check fairly.

• Bing:Implementing a cash-only system

"Andrew" won't shop at places that don't accept his American Express card: "Having all of my transactions in one place each month is easier than living on cash for me. Plus, I'm not willing to spend any $$ if it doesn't translate into SkyMiles." Post continues after video.

A couple of readers don't carry money unless they have specific plans -- and since they never take cabs or use vending machines, they don't worry about the lack of lucre.

On the other hand, several readers wrote that using cash keeps them from overspending. As their dollars dwindle, they know exactly how much they've gone through that day. A lighter wallet doesn't lie.

• Calculator:Is your budget in balance?

But "Leland" has trouble keeping track of cash. An itemized debit card statement works better. The only exception is when she hits the ATM for an evening out with friends: When she's out of folding green, it's time to say good night.

For me, some of each
I've been using cash more lately because I brought back a fair amount of it from my recent trips to Los Angeles and Phoenix. That could be because I overestimated how much I'd need. It could also be that spraining my ankle while I was away meant fewer excursions and therefore less money spent.

Generally I use cash only for small purchases, such as a book of stamps or a bunch of bananas. For everything else I use my rewards credit cards. Points from one of the cards helped pay for my Christmas gifts this year, and I plan to take another frugal trip to Alaska this summer with points from a second card.

• Find a better credit card

But if I had a problem with impulse spending, I'd definitely go cash-only. Using plastic works for me only because I don't buy anything that I can't pay for when the credit card statement arrives.

Not everyone has that kind of self-control, which is why I'm concerned when people eschew cash entirely. Swiping a credit or debit card can give the delightful feeling of having obtained what we want without actually having to pay for it.

On a cash-only system you know that once your walking-around money is gone, it's time to go home. (Right, Leland?) Plastic makes it easy to announce, "Next round's on me, and let's get some appetizers, too!" You might not do that if you had to take actual money out of your wallet to pay.

In addition, cash can be a good reminder of how salary translates to spending. Suppose you're making $10 an hour. You want to buy a shirt on sale for $20. Hold a double sawbuck in your hand: It represents two hours of answering phones/throwing pizzas/pulling coffee. Is it worth two hours of work just to get another garment?

That goes for food, too. Using cash will remind you of a very depressing fact: With tax and tip, I just spent two hours' worth of salary on a burger, fries and beer. If you use plastic, it's so easy just to sign and forget.

On the other hand, paying with real money at least means you haven't turned into that guy.

Readers: How much cash do you carry? Why that amount? Does using cash help keep you on a budget? And if you're not sure, have you tracked your spending lately?

MSN Money columnist Donna Freedman blogs at Smart Spending and Surviving and Thriving.

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