No one wants a big payday to morph into a beastly tax burden. So while the best tax strategies are usually those crafted long before you actually collect any income, there are some last-minute moves that can help shelter at least a few of those zeros—even for those with poor planning skills.

1. We're In the Money

However, Steve Parrish of Principal Financial Group notes that spreading the sale of corporate stock can bring other concerns. "You run the risk of something like Enron's stock," he says. "It could plummet."

So while selling that heap of options all at once creates little opportunity for protecting the gain from tax, Parrish is sanguine on the situation.

"With capital-gains tax at just 15 percent, there's an argument that it will never be this low again," he says. "In the 1990s there was almost no difference between ordinary income tax and capital-gains tax rates. Now there is more than a 50 percent difference. This is the lowest I've ever seen."

2. Web 2.0 Venture Pays Off

That provision allows them to sell stock in their original venture and plow all of that capital into a new launch—without paying tax on the gain. The only restrictions: The new investment must occur within 60 days of the stock sale and it cannot exceed $10 million.

This one's a favorite of venture capitalists, says Alan Olsen, of Greenstein, Rogoff, Olsen & Co., a leading Silicon Valley C.P.A. firm. "And if you keep starting new companies, that capital can stay protected," he says.

The rest of the money? That's subject to capital-gains tax of 15 percent.

3. The Wall Street Bonus

But Tad Borek, a lawyer and investment adviser in San Francisco, suggests that traders uncork some losses to offset that gain. And losses are sadly likely to be in abundance this year.

"If you already have ordinary income from regular bonds, for example, or a money market fund that's generating interest, get rid of those and put the capital into municipal bonds or a tax-exempt money market," Borek says. "These may pay less but you need to bring down your income—and cut the tax bite for this year."