This week, the dollar hit a new low against the euro, which is now more than $1.40.
For the first time in 30 years, the greenback is worth the same as a Canadian dollar.
That may be a source of pride for Canadians, whose currency is nicknamed the "loonie" and has never gotten much respect, but it means headaches for markets at home and abroad.
The United States is now less attractive for foreign investors. Exporters to the United States also suffer, and everyone is paying higher gas prices, since oil is traded in dollars.
A weak dollar also increases the risk of inflation at home.
But for tourists, it can be very, very good news -- unless, of course, you're American.
Canadians, for the first time in decades, are coming south across the border to find bargains.
Europeans are also coming to the U.S. to shop.
"They're going to places like Abercrombie and Fitch, Tiffany's, Nike and Levis," said Chris Haywood of New York City's tourist board. "They're leaving again with heavier suitcases and wallets that haven't quite been emptied out."
Meanwhile, Americans traveling through the United Kingdom, where a pound costs $2, are paying $6 for their Starbucks latte or a whopping $7 for their Big Mac.
"It's pretty much one meal a day, is what we've been buying," said Jerry, an American visiting London with his family.
But, Americans who stay at home don't escape the cost of a weak dollar, since anything imported costs more -- that means everything from a designer suit to a bunch of bananas.
ABC News' David Wright and Hanna Siegel contributed to this report.