Sorry to hear about the firing, but you're at least fortunate in that California law protects employees in your situation. Your employer is required to hand over your final paycheck immediately upon firing you (or within 72 hours if you work in a seasonal industry, like farming).

In addition, in California, your final paycheck must include payment for all of your accrued vacation time (though not sick time) -- no buts about it.

If you get any flack from the one who holds the pursestrings, cite chapter and verse of the law: California Labor Code, Sections 201 and 202. And if that doesn't work, get in touch with the state department of labor.

Every state has its own rules regarding final paychecks. Employees in other states can refer to Nolo's Chart: Final Paychecks for Departing Employees or contact their state labor department.