I don't typically carry much cash. Sometimes I go weeks without more than $1 in my wallet. And because I'm not much of a cash spender, I don't pay much attention to where it goes. But boy does it add up.

According to a new survey commissioned by Visa, U.S. consumers have no clue where about $21 per week in cash goes. That adds up to almost $1,100 annually. (The survey's subtext: Use Visa debit and credit cards).

I took a peek at my spending trends in Mint.com and learned that my family has no idea where we spent approximately $1,300 in 2009. But since that's for two of us, I guess we're better than average.

Still, that's a lot of dough. Oh the meaningful ways I could have spent that $1,300. A new lap top, a vacation, a house cleaner. Or even better, just think of the ways I could have saved that sum.

More findings from the survey:

  • younger adults between the ages of 18 to 24 claim to lose track of $2,500 annually, more than twice the average amount.

Consumers said they were most likely to mystery spend while:

  • 34% Purchasing food and other groceries
  • 32% Leisure shopping for non-essentials
  • 31% Enjoying a night on the town
  • 26% Dining out

I'd put "giving money to kids for school fundraisers, etc." on that list. I surprised not to see that proverbial $3 latte.

About two in 10 consumers said small cash purchases make it hard to track spending. I'm guessing that the other eight have never even tried to track their spending.

Will the survey's findings or my own cash leak prompt me to be more vigilant with my cash tracking in 2010?

Honestly, I doubt it. While the amount is significant, it's a relatively small portion of the money we bring home and spend each year.

Tracking cash is just one other thing to do. I have no time or brain power to devote to that tedious chore. I'll just continue to carry very little cash and to make most of my purchases with easy-to-track plastic.

But if you are determined to better track your cash, or need to because you're living on the edge and have to curb that credit card debt, I suggest picking the one or two categories with the largest money leak and focus on tracking them. Counting every penny is bound to be eye-opening.