Rent with somebody you trust. Most likely, that means renting via a worldwide service like HomeAway, or with city-specific specialists such as Rentals in Paris or Haven in Paris. With these sites, you can read feedback on rentals from other travelers, and you can rest assured that any would-be scammers will quickly be sniffed out and booted. If you're unsure of a company, look to see if consumers have filed complaints about it at the Better Business Bureau. As for finding a rental via Craigslist, proceed with extreme caution—we've all heard stories of people being ripped off on Craigslist.
Always pay with a credit card. Sending a check—or worse, sending money via Western Union—is unwise. Use plastic instead, because your card company provides several layers of protection, namely a safeguard to reimburse you for services not rendered.
Ask specifically about the owner's right to rent. If you're at all concerned that the owner may be violating local housing regulations, ask directly what's up—and whether the owner can prove there's no lawbreaking going on. Owners who list properties with a major service like vrbo.com are required to abide by local laws and will be kicked off the sites if they're found in violation.
Get everything in writing. You need a contract, and you need to read it carefully—especially when it comes to components regarding cancellation rules, the terms and schedule for the return of your deposit, and any fees above and beyond the rental rate (e.g., cleaning fees, taxes, etc.).
Monitor the news. And pay particular attention if you're renting a place in New York City after May 1, 2011, when new rules go into effect—and when no one is completely sure how, when, why, and what rentals will be affected.
Be a considerate guest. Housing authorities hear about short-term rentals from the complaints of neighbors. So if and when regulations are enforced, it stands to reason that authorities will target apartment buildings and pseudo hotels where there's a frequent turnover of loud, unruly transient guests.