More and more hotels are tacking on hidden fees to your hotel bill. According to accounting firm PricewaterhouseCoopers, hotels will charge travelers almost $2 billion in hidden fees and surcharges in 2007.

That’s up from just $550 million just four years ago. These days, most hotels and travel websites often won’t disclose all of their charges up front, especially on the Internet.

Among the most common fees that aren’t normally disclosed are housekeeping fees, early check-in and check-out fees, internet service charges, and in-room safe surcharges. You’ll need to ask the hotel directly about these fees, because third-party websites and brokers don’t always know — or care to mention — these charges. So allow yourself a little extra time at checkout. That way, in case there are any surprises, you’ll be able to contest the charges in person before you have to rush off to catch a flight.