An impressively frugal woman from the Boston area has managed to save $12,000 over the course of three years by just holding onto all her $5 bills.

At Get Rich Slowly they have this excerpt of how she did it:

This idea will only work if you are disciplined. When I decided to save my fives, I meant it, and I save every one. No exceptions. (OK, once on the Mass. Pike I gave the toll collector a 20 and he returned three fives and four ones. I panicked. This was my allowance for the week. I asked him to give me a ten and more ones instead.) Otherwise, if I get a five dollar bill back — at CVS, or Starbucks, or Marty’s on Washington Street — I tuck it away, smiling.

When the fives pocket in my wallet reaches $50, I make a deposit in my credit union. When this account reaches $2,000, I buy a CD to earn higher interest. Also, it helps to pay with cash. You can’t get a five back if you’re always using credit cards.

I commend her for the type of self-discipline needed to get this done. However, I don’t think I could part with all my $5 bills. I was having a debate with the girlfriend about how fivers are the best bill to have. Honestly, if you’re the dope wandering around with a $20 bill, you’ll look like a tool when you try to pay for a 5-dollar beer or a 7-dollar meal. And when it comes to 1s, the less you have the better you’re off. You don’t always want to feel like you’re at the strip club, right?

So I guess that narrows it down to 10s and 5s. (Obviously 50s and 100s are great if you’re a high roller, but for the majority of everyday purchases, they are pretty inconvenient). I say the 5 trumps the 10 because it’s more divisible, but it’s up for debate.

Let’s settle this with some input from the comments section.

GetRichSlowly:Turning $5s Into Thousands, July 21, 2008 via Consumerist