You certainly have a right to be paid for work you already did. Most states have a law specifying exactly when a final paycheck must be issued to employees who resign or get fired. Some states, recognizing that an employee who gets fired probably has a more pressing need for a paycheck than an employee who quits voluntarily, require employers to pay fired employees more quickly -- often immediately or within one or two working days of the termination. (You can see the rule in your state at Chart: Final Paychecks for Departing Employees.)

State laws vary more widely on unused vacation time. Some states require employers to pay employees for accrued vacation time; others do not. And in a few states, the employer's own policies dictate whether employees are entitled to be paid -- if the employer's policy says that employees will be paid for unused vacation time, the employer must make good on the promise.

To find out more, check out Your Rights in the Workplace, by Barbara Kate Repa (Nolo).