Investors can offset capital gains and losses on a dollar-for-dollar basis, with no limit. If your losses exceed your gains, or if you have no gains at all, you typically can deduct as much as $3,000 of net capital losses ($1,500 if you're married and filing separately from your spouse) from wages and other ordinary income. Additional losses are carried over into future years.

But if you sell and decide to reinvest the proceeds quickly, be careful you don't run afoul of what are known as the "wash sale" rules. You can't deduct losses from sales of stock or other securities in a wash sale, which typically occurs when you sell or trade securities at a loss and buy the same, or "substantially identical," securities within 30 days before or after a sale.

If an investor does sink money into a fund just before a sizable year-end distribution, there is at least one consolation, according to the Ernst & Young Tax Guide 2008. Your higher basis will reduce the amount of any capital gain on a later sale -- or, if you sell the fund at a loss, it will increase the size of your capital loss. However, the guide says, "if you want to limit your current tax liability and lower your basis in the shares, you should delay your purchase of fund shares until after the record date for the distribution."

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Many workers will pay higher Social Security taxes next year.

The maximum amount of earnings subject to the Social Security tax in 2009 will be $106,800, the Social Security Administration said. That's up $4,800, or 4.7%, from $102,000 this year. This dollar threshold is adjusted annually to reflect changes in average wages.

Thus the maximum additional Social Security tax that might be collected on an employee earning above the 2008 wage base will be $297.60, says Avram Sacks, Social Security law analyst at CCH, which provides tax and payroll information and software and is part of Wolters Kluwer Law & Business.

"Taxes for self-employed individuals use the same earnings base, but the rates are double those of employees, since the self-employed must also pay the 'employer' portion of the taxes," says Mr. Sacks. "This means that high-earning, self-employed individuals may owe as much as $595.20 in additional self-employment tax in 2009. However, they can recoup some of this amount through a deduction on their federal income tax."

Of the estimated 164 million workers who will pay Social Security taxes in 2009, about 11 million will pay higher taxes due to this increase in the taxable minimum, the Social Security Administration said.

The rate for the "hospital insurance," or Medicare, tax stays at 1.45%. This applies to every dollar you earn.