According to the Tax Act of 2001, if adjusted gross income is below $30,000, 50% of contributions to an IRA or 401k is eligable for a tax credit up to $2,000. I am retired, but working part-time. My question: Does this include a Roth IRA? Also, can the $2,000 be a combination of Roth IRA and 401k?

YES

However, there are rules that may reduce the amount eligible for consideration if you have taken ANY withdrawals from your IRA or Roth in the year of the credit AND the TWO years prior AND any withdrawals up to the time your tax return is due. 39 1/2 months.

I believe that students do not qualify for the tax credit. I seem to recall reading something about this but can't remember where.