We’ve talked up staying with locals when you travel as a good way to help you get a better feel for your destination and save money. Here’s more on the saving money part.

With the dollar still tanking, for Americans, traveling overseas – especially in Europe – is more and more expensive. So begins the latest of Arthur Frommer’s budget travel columns; about taking the sting out of the dollar/pound conversion with homestays in London.

When I wrote my first travel guide, the U.S. dollar bought three British pounds. Today, the U.S. dollar buys — are you ready for this? — one-half of one British pound; it takes about two U.S. dollars to buy a pound.

Since the average London guesthouse — a modest 15-room guesthouse, not a hotel — charges as much as 100 pounds for a room with a twin bed, the outlay comes to a startling $200 a night. London ranks with Oslo as the most expensive cities in Europe.

Skip the guesthouses, Frommer advises, and go with a cheaper, though maybe farther out, room in the home of a Londoner: With rates as low as $46 a night (for a single), you might save as much as $100 a day on lodging alone. Frommer lists three London homestay agencies in the column.

But homestays aren’t just a London thing. Plugging his daughter Pauline’s book “Pauline Frommer’s New York City”, Frommer says that sleeping in homestays is a growing trend in NYC, given the skyscraper-high prices of hotels in Manhattan. Makes sense. I punched homestay+“New York City” into Yahoo! and found dozens of agencies, including some in Washington, D.C., Los Angeles, and other cities in the U.S. and around the world. None of the three London agencies Frommer mentions turned up in the top ten of a simple search, though. So if you’re thinking of giving a homestay a go, maybe one of Frommers’ books is worth a look. Tim Leffel gives a good overview of homestays here, too.