JUST SAY THE words conspiracy theory and most people will picture a guy wrapping his head in tinfoil and bottling his urine to keep the aliens from taking him out the way they did JFK. But not all conspiracies are crackpot. Some are very real--and costing you real money. So without further ado, we give you seven things they don't want you to know.

1. FAUX GAMBLING DEBTS

The Unlawful Internet Gambling Funding Prohibition Act blocks the use of credit cards to pay for online gambling. But most gambling sites ignore this. However, if when the time comes to pay, you stop payment, there's nothing they can do. Most will blacklist you--but if the choice is between never gambling on the computer again or ponying up $5,000, the decision should be simple.

2. EVERYTHING'S COVERED

Few policyholders know it, but most renter's insurance covers your property as well as your home. Out at a bar and got your camera stolen? They'll cover it. Lost your luggage on vacation? Same deal. For about $300 a year, it's the best bargain this side of forced labor.

3. TAKE IT BACK--ANY TIME, FOR ANY REASON

Sure, clothing companies such as J. Crew offer a "lifetime guarantee" But the fact is, nothing has to tear or break for you to take them up on their offer. Really. Send them a letter as dopey-sounding as "Due to changing styles, I no longer like this shirt. I regret having kept it so long," and they'll send you back a new shirt or your cash. Even if you bought it years ago--guaranteed! Give it a try. We did, and voila: An old wardrobe is new again.

4. CASH IN ON COMPLAINTS

A "satisfaction guarantee" works pretty much the same way. If you're not satisfied, for any reason, the vendor has to make it up to you either in service or with a refund. Until recently, Amtrak lived by this code, but discontinued it after too many riders got free tickets for saying things like, "I thought this trip would be faster." Fortunately, many hotel chains, including Hilton, still give you that "100% satisfaction guaranteed" Tossed and turned last night? Felt the shower was lacking? Let them know and it's on the house.

5. THE PAPER'S WORTHLESS

According to Shoppers Charge Accounts--a company that monitors 800 stores nationwide--88% of gift certificates from those stores go unused yearly. Translation: That $60 piece of parchment you gave to dad is just that--and utterly worthless unless he plans to take notes on it. You've just bought nothing.

6. IGNORE THE EXPIRATION DATE