Americans gave up $67 billion worth of vacation days in 2010

The average employed American worker got 18 vacation days last year, but only used 14 of those desirable days off, according to a 2010 survey by Expedia.com.

Alternatively, workers in France got 37 vacation days last year and used 35 of them while the average worker in Great Britain received 28 vacation days and took 25, Expedia said.

Meanwhile, those four forfeited days of vacation per person add up quickly. Altogether, Americans gave up 448 million earned but unused vacation days in 2010. Considering the average wage of $39,208 for a full-time worker -- that's $67.5 billion worth of time.