We did this unintentionally as well. Dh changed jobs and was given a check for all of his unused vacation time...$9,055.00. Holy shit!
The check was nice and is now sitting in an IRA, but damn, man. In the years that he was accruing vacation, you know what he wasn't doing? Taking some damn time off to be with his family.
And yes, this is a lousy way to save money, but an excellent way to piss off your spouse.