I'm looking for a chart which basically gives the gross pay
thresholds, arranged by marital status/allowance combination, which a
U.S. employee must exceed in a pay period before Federal tax is
withheld from their paychecks.  I have such a chart for 2005 but would
like to be directed to one for 2006 that is arranged in the same
specific format (or, alternatively, if someone can print the info here
and cite a webpage with the data they used to make the calculations). 
 I could not find this info on the IRS website though that doesn't
mean it isn't there.

Here is the 2005 chart I have.  The 2006 one should follow the same format.

             FOR WEEKLY PAYROLL
Exemptions  /  Gross  /  Fed Tax Withheld 2005
----------     -----     ---------------------
Single 0      $55.00     $0.00
Single 1     $115.00     $1.00
Single 2     $180.00     $1.00
Single 3     $240.00     $1.00
Married 0    $160.00     $1.00
Married 1    $220.00     $1.00
Married 2    $280.00     $1.00
Married 3    $340.00     $1.00

            FOR BI-WEEKLY PAYROLL
Exemptions  /  Gross  /  Fed Tax Withheld 2005
----------     -----     ---------------------
Single 0     $105.00     $1.00
Single 1     $230.00     $1.00
Single 2     $350.00     $1.00
Single 3     $480.00     $1.00
Married 0    $310.00     $1.00
Married 1    $440.00     $1.00
Married 2    $560.00     $2.00
Married 3    $680.00     $1.00

The 3rd column is of little importance to me and can be omitted if you wish. TIA

Hello Brave3,

Using as a reference, the IRS publication at
  http://www.irs.gov/pub/irs-pdf/p15.pdf
(scroll down to tables starting on page 38)
  http://www.irs.gov/pub/irs-pdf/p15a.pdf
(scroll down to tables on page 24), the following table should be used
for 2006. For the most part, the values are very close to those from
2005. The "Gross" numbers below are from the first reference. I noted
some slight differences in the results using the calculations from the
supplement, and either method is OK as long as you are consistent in
what you use.

             FOR WEEKLY PAYROLL
Exemptions  /  Gross  /  Fed Tax Withheld 2005
----------     -----     ---------------------
Single 0      $51.00     $0.00
Single 1     $120.00     $1.00
Single 2     $185.00     $1.00
Single 3     $250.00     $1.00
Married 0    $160.00     $1.00
Married 1    $220.00     $1.00
Married 2    $290.00     $1.00
Married 3    $350.00     $1.00

            FOR BI-WEEKLY PAYROLL
Exemptions  /  Gross  /  Fed Tax Withheld 2005
----------     -----     ---------------------
Single 0     $105.00     $1.00
Single 1     $235.00     $1.00
Single 2     $360.00     $1.00
Single 3     $490.00     $1.00
Married 0    $310.00     $1.00
Married 1    $450.00     $1.00
Married 2    $560.00     $2.00
Married 3    $700.00     $1.00

Alternatively, from the supplement, similar values can be calculated
by taking the first "but not over" value in the table for the "Single
0" or "Married 0" value. Each row following is incremented by $63.46
(for weekly) or by $126.92 (for biweekly) for each allowance as
indicated in the header of the IRS tables referenced. If you use a
spreadsheet or other computerized method - the formulas in the
supplement may be easier to implement than a strict look up table.
Please make a clarification request if you need these alternative
results.

To find this, I used the following search string:
  site:irs.gov tax withholding 2006
and reviewed the links to the publications.

Please make a clarification request if you find the answer incomplete or unclear.

  --Maniac