Some quick things to consider doing before the end of the year if you're in a situation similar to mine: (I made a lot of money in 2008 and none in 2009)
#1 If you have any stock / mutual fund investments for which you have a capital gain, you can sell them and take advantage of the 0% long term capital gain (and reduced short term capital gain) that exists for incomes under $34k/yr. Capital gains tax rates
#2 If you have a traditional (not Roth) IRA, you can convert it to a Roth IRA at your current tax rate. If your current tax rate is unusually low but you expect to have a moderate tax rate when you retire, this may be a good idea. (There are a lot of tax laws and exceptions here, so it's less of a no-brainer than #1.)
#1 If you have any stock / mutual fund investments for which you have a capital gain, you can sell them and take advantage of the 0% long term capital gain (and reduced short term capital gain) that exists for incomes under $34k/yr. Capital gains tax rates
#2 If you have a traditional (not Roth) IRA, you can convert it to a Roth IRA at your current tax rate. If your current tax rate is unusually low but you expect to have a moderate tax rate when you retire, this may be a good idea. (There are a lot of tax laws and exceptions here, so it's less of a no-brainer than #1.)