Air travelers inadvertently gave the TSA more than $638K in change last year

No matter how calm, cool and collected you might be when you walk into the airport security line, by the time you get to the other side of the full body scanner, you just want to grab your shoes and your belt and leave everyone in a blue uniform behind you. One consequence of the stressful security experience? Air travelers left a lot of coins in the corners of those plastic bins: $638,142.64, to be exact.

That precise amount is what the TSA collected in 2013, according to its own calculations (The agency is still counting all of the change from last year —that, or swimming around in it, Scrooge McDuck-style). That dollar amount is an all-time high in inadvertent donations, more than the $531,395 collected in 2012 and $409,085 in 2011. A TSA spokesperson told CNBC that the agency expects the amount to increase every year going forward, but did not elaborate on the reasons why.

The TSA is required to report every quarter, dime and nickel to Congress, but what happens to it after that? The agency essentially gets to say "finders, keepers." The TSA is currently required to spend the money on civil aviation security, but it is not using very much of it. In 2012, for example, the TSA cashed in $6,500 to translate some airport signs into foreign languages and to cover some vaguely described administrative costs.

Some legislators have suggested that the agency should be required to actually do something with the money besides, you know, keeping it. In 2013, Rep. Jeff Miller (R-Fla.) proposed the TSA Loose Change Act which would have transferred all of that unclaimed money to non-profits like the USO that provide airport services to members of the armed forces and their families. The act passed the House but then died a quiet death with the Senate's Commerce Committee.

So how can you keep the TSA from getting its hands on your coins? If you're flying through Columbus, Ohio, Denver or Phoenix, several non-profits have set up collection points before the airport's security area. Last year, travelers donated more than $88,000 to Denver's Road Home, an organization that provides resources for the homeless. Somehow that seems more meaningful than chipping in to help the TSA translate an airport sign.