Peter Greenberg is the travel editor for NBC’s Today Show and he is the chief correspondent for the Discovery network’s Travel Channel. His book, Hotel Secrets from the Travel Detective is a controversial tome of information that has been accused of being a bit smug and self-promoting. On the other hand, the cunning traveler may find it useful as a guide for taking advantage of every possible deal and shortcut in the hotel business.

Some secrets he shared a few years ago with Bottom Line Secrets include the following:

• It’s often possible to beat a hotel’s best advertised price by 20%, particularly if you call just a few days before your visit. First, shop around for the best deal on a third-party Internet travel site, such as Expedia.com or Hotels.com. Don’t take the deal—just jot it down.

Then call the hotel and explain to a manager or director that you know these Web sites mark up room prices by 20% to 40%. Tell the manager you would like to split the difference—say you’ll pay 20% below the price you found on-line. Unless the hotel is filled to capacity, the manager is likely to take you up on your offer.

More tips after the jump.

• It pays to tip the housekeeper every day. Exchange a few pleasant words with the housekeeper if you see him/her—and leave a $2 or $3 tip each day. You’ll get better service—housekeepers are the most overworked, underpaid, under-appreciated people in the hotel, so any gesture will be appreciated.

Knowing the housekeeper also reduces the chances that your room will be burglarized. Dishonest housekeepers are less likely to target guests they have met. If a thief enters your room while it is being cleaned and pretends to be you—a common ruse—the housekeeper will be able to spot the impostor.

• Hotel rooms are infested with germs. Certain items in hotel rooms never get cleaned. The biggest trouble spots include the TV remote control, telephone and clock/radio. Travel with a package of antibacterial wipes, and clean these items when you arrive.

• Lost-and-found is a great resource for cell-phone users. If you use a cell phone, odds are that someday you’ll forget to bring your recharging cord or lose it in transit. If you’re staying at a hotel, there’s no need to buy a replacement. Recharging cords are the number-one item left behind in hotel rooms. Most hotels are willing to lend cords from their lost-and-found—but guests rarely ask.

• Not all concierges are really concierges. A true concierge is the most connected person in town. He/she can get tickets to sold-out events… reservations to popular restaurants… prescriptions filled in the middle of the night… even a new heel on a shoe by 8 am. (A tip of $10 to $20 usually is appropriate—more if the concierge really worked miracles.) But not all hotels that advertise “concierge service” truly offer it. Many simply assign a regular hotel employee the role each shift.

An elite concierge wears a gold key on his lapel. It’s the symbol of Les Clefs d’Or—French for “Keys of Gold” — a prestigious international concierge organization.

Several more tips Greenberg offers can be found here:

Ten Secrets That Hotels Don’t Want You To Know [bottomlinesecrets.com]