With a short work week before New Year's, you'll probably be busy getting ready for another three-day weekend. But before you say goodbye to 2011, you need to consider making a last-minute move that could save you thousands in taxes over the long haul.

I know -- it's pretty early for most people to be thinking about their taxes. After all, you've got until mid-April before you have to file a tax return, and you won't even start getting the documents you need to prepare your return until the middle of January. But that's no excuse not to start doing some tax planning. And with the strategy I'm about to describe, if you don't get it done by Saturday, you'll miss what may prove to be your best chance to use it.

It's all about retirement
Tax planning and saving for retirement go hand in hand. That's because you have several useful tools at your disposal to help you save taxes while boosting your retirement savings at the same time. Through 401(k) plans at work, millions of workers contribute money toward their retirement with every paycheck, with some being fortunate enough to get their employers to match part or all of their contributions. In addition, anyone has the ability to save additional money in a personal IRA.

But one aspect that fewer people ever consider is whether to use a regular IRA or a Roth IRA for their retirement savings. Regular retirement accounts give you an up-front tax deduction. But for long-term investors, Roth IRAs give you something that may prove more valuable: tax-free income that lasts not only while you keep your money inside your IRA but also when you take it out. That's an advantage no regular IRA provides.

Still, until a couple of years ago, many taxpayers were locked out of Roth IRAs by income limitations. Starting in 2010, the IRS allowed you to convert existing regular IRAs and 401(k) accounts into Roth IRAs.

The paradox of Roth conversions
The reason so few people convert to a Roth is that it creates a higher tax bill now. You have to include the amount you convert as taxable income, which boosts your taxes.

So why would you ever want to convert? One reason is that lately, many taxpayers have suffered through tough times, seeing their income fall during the recession. As a result, you may be in a lower tax bracket than normal. If that's the case, then taking advantage of temporarily low tax rates to convert part of your IRAs to Roths essentially locks in those low rates forever.

Another reason has to do with the way Roth conversions let you get a free do-over if things don't work out. Basically, you have the right to undo your Roth conversion anytime between now and Oct. 15. So if your investments do well, you get to keep the tax-free gains in your Roth; but if they go down, you can recharacterize your conversion and put the remaining money back in your old IRA -- undoing the tax impact of converting.

What that allows you to do is to take a flyer on some high-risk bets. Here are just a few ideas:

  • Gold prices have slumped from their summer highs, and small miners like Brigus Gold (AMEX: BRD), Primero Mining (NYSE: PPP), and Silvercorp Metals (NYSE: SVM) have all seen pretty sizable declines. But if you think metals are poised for a comeback in 2012, getting money into a Roth to invest in them could produce even better after-tax gains.
  • Several promising biotechs, such as Momenta Pharmaceuticals (Nasdaq: MNTA) and Arena Pharmaceuticals (Nasdaq: ARNA), have made impressive moves in the past few months. Whether they continue to post gains or flare out like competitor Avanir Pharmaceuticals (Nasdaq: AVNR) has done is an open question. But with a Roth conversion, you can benefit either way.

That's not to say that you can't use a Roth for a basic investment as simple as SPDR S&P 500 (NYSE: SPY) if you want. But the recharacterization trick opens up some interesting strategies -- if you're willing to dig into them further.

Take a look today
Roth conversions will still be available next year, but if you see your income going up, then you may pay more in taxes if you wait. So don't let 2011 end without at least taking a look at your tax situation. Doing a Roth conversion might be the best move you could possibly make.

But a Roth is just one piece of putting together your overall retirement puzzle. Our latest special free report reveals the shocking can't-miss truth about your retirement -- and what you can do to address it. Grab a copy today and find out everything you need to know.