What was the income tax before 1912 and the 16th amendment?
Well, actually before 1913 the idea of an income tax was prety much thought to be unconstitutional BUT ...
There was one tried in the Civil War era - 1862/63 as I recall and I've got a copy around here somewhere (kinda moth-eaten and dusty, though). It didn't last long I think because of the legal problems but it WAS passed into law and put into effect.
The income tax was first begun during the 1860s to finance the War.
For a brief history, see the IRS website.
http://www.irs.gov/irs/article/0,,id=98142,00.html
While the Supreme Court later struck down certain income taxes as unconstitutional, to pin ones hopes on the whim of the Supreme Court continuing to hold that income taxes are direct taxes (especially when the government has a history of collecting income taxes before the 16th amendment) seems pretty foolish to me.