If you're among the richest people in the world, chances are you've found some unusual ways to spend your money.
That's what tech executives like Larry Ellison, Jeff Bezos, and Elon Musk have done, anyway - they've spent money on everything from a massive chunk of the state of Hawaii to the submarine car from the James Bond film "The Spy Who Loved Me."
Some tech billionaires are famously frugal, while others spend money on more conventional expenditures like mansions or fabulous vacations. And while the tech billionaires featured below own their fair share of homes and yachts - plus found time for more noble pursuits like donating to charity or signing the Giving Pledge - they've also used their billions to pursue passion projects.
Here are some of the more unusual and extravagant ways tech executives have spent their money.
Many CEOs make expensive home and land purchases, but perhaps none more so than Oracle founder Larry Ellison. In 2012, the billionaire purchased 98% of the Hawaiian island Lanai.
Unsurprisingly, Tesla and SpaceX CEO Elon Musk has an interest in unusual vehicles. In 2013, for example, he bought the Lotus Esprit submarine car that's used in the James Bond movie "The Spy Who Loved Me." Musk paid $920,000 at auction.
Amazon CEO Jeff Bezos has invested $42 million in a mechanical clock that's buried inside a mountain in Texas.
Bezos has a passion for space, as evidenced by his Blue Origin rocket company. In 2013, the exec also funded an expedition to retrieve the remains of multiple Apollo engines from the bottom of the ocean.
Google cofounder Sergey Brin has reportedly invested between $100 and $150 million of his own money in building a 600-foot flying airship.
Brin's fellow Google cofounder Larry Page is also interested in flying vehicles, though of a slightly different variety: Page funds three different flying car startups.
And while many high-powered executives have private planes, Page and Brin one-upped the typical Gulfstream jet. In 2005, they bought a former passenger plane, a Boeing 767-200.