If Congress does act to retroactively reinstate the donation rule, the gift will be excluded from income just as under the pre-2012 rule.

FORBES: The IRA Charitable Donation in 2012

Don't forget about state tax benefits: "A direct IRA donation often provides a state tax benefit because it lowers income, while other charitable gifts can be limited or disallowed, " says Mr. Lifson.

WSJ: Tax Report: IRA Donations Get a Break

The newly extended enhanced incentive allows a non-farmer donor to use a conservation donation deduction to wipe out 50% of his gross income in any year, up from the normal 30% that is a permanent part of the law.

FORBES: Good And Bad News For Conservationists In New Tax Law

Thus, for the well-heeled sports fan sitting court-side, the federal government rebates more than one-quarter of the required donation. (80% of the top income tax rate, 35%, equals 26%.) Since the deduction carries over to state income taxes, most states also implicitly rebate a portion of the cost.

FORBES: Repeal the NCAA Ticket Tax Break

Otherwise, Dell.com's checkout page might start looking like New York State's income tax return, which last year had seven opt-in donation candidates, like exploited children and prostate cancer research.

FORBES: Dell's Opt-In Environmentalism

The record-breaking donation meant Oxford could abolish an increase in tuition fees for students from low-income families.

BBC: Sunday Times Rich List: Michael Moritz hits Wales top spot

Guests pay an agreed donation - often in advance to cover "no shows" - providing the artists with a guaranteed income, often more generous than their share from a larger commercial event.

BBC: House concerts bring magical music into front rooms