You may be familiar with the intrauterine device (IUD), a once unsafe birth control tool that by 2013 was the top choice for more than 10 percent of women using contraceptives, according to the Centers for Disease Control and Prevention.

But you might be surprised to learn that a Warren Buffett-connected charity provides funding support for the IUD. It's the Susan Thompson Buffett Foundation, named after his first wife.

Over the past 10 years, the foundation has emerged as "the most influential supporter" of IUD research and making the device more available, Bloomberg reports. It calls the movement to IUDs "the biggest shift in birth control in a generation."

So what is Buffett's thinking?

"For Warren, it’s economic," Judith DeSarno, the Buffett Foundation’s former director for domestic programs, said in a January 2008 interview for a birth control history project that was just released, Bloomberg reports.

"He thinks that unless women can control their fertility — and that it’s basically their right to control their fertility — that you are sort of wasting more than half of the brainpower in the United States."

In other offbeat Buffett news, for those of you concerned about haircuts — and here we're talking about real cuts, not the financial ones likely to be suffered by holders of Greek and Puerto Rican debt — MarketWatch reporter Charles Passy offers a newsflash.

Hillary Clinton recently received a haircut at a fancy New York salon that normally charges $600, according to the New York Post, while Warren Buffett reportedly pays $18 per cut. That makes Clinton's cuts 33 times more expensive than Buffett's.

To be sure, Clinton has nothing on 2008 Democratic presidential candidate John Edwards, who reportedly paid $1,250 per trim.

Passy earned an exclusive interview with Buffett's Omaha, Neb. barber, Stan Docekal, who plies his trade for the investment legend every two or three weeks. "I let him do his thing," Docekal said. And what does Buffett do while he's in the chair? He usually watches TV news, the barber reveals.

Related Stories:

• Buffett Gains Tax Benefit From Billion-Dollar Charity Donations
• Telegraph's Quinn: Buffett's Fall on Wealth List Signals 'Crown Starting to Slip'