If you're anything like me, filling out your yearly tax forms is a dreaded slog through forms, schedules, pay stubs, and other scraps of paper with arcane numbers and codes printed on them. Then, after a weekend of reading and re-reading, you send your tax forms to the IRS. Hopefully you're in for a little refund. But for those less fortunate ones, their civic act culminates in a check made out to Uncle Sam. Once you hand over your due, where does it go? Ever wonder just what it means to your bottom line if you're married but file separately from your spouse? or what if you're single? How much of a difference does it make if I take that raise at work?