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>>For 2005, it's $90,000.
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>So for 2005 if I had let say $80,000 in employer paid wages and $20,000 in independant wages I need to pay about ~15% for $10,000 of independant wages and $10,000 would fall above the cap.
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>For the payroll option:
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>If I have 2 employers and neither knows what the other pays, they will pay 7.5% and deduct 7.5% from my check for wages even if the total is over the $90,000 cap. I wonder what happens to that money?

When you do your taxes, the overpayment should be subtracted from your taxes owed resulting in a decrease and/or a refund. You would use the long form of 1040 Schedule SE if you made over $90,000.