NEW YORK (Money Magazine) -- The gadget industry depends on your remaining ignorant. Otherwise you'd know that contrast ratios (a flat-screen TV spec) are basically bunk, that megapixels in digital cameras have become almost irrelevant, and that good marketing doesn't always equal good technology (applies to everything).

So keep your head on straight when you walk into an electronics store. Is it a small, independent operator that's been recommended by a friend? Avail yourself of all the reps' professional advice - keeping in mind that they care for their bottom line, not yours.

Samsung's A900, $100 (with contract), is almost as thin as the Motorola Razr and easier to use.

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Larger, big-box retailers? Do some research on your own and go there simply to buy something and carry it out of there.

You can't count on their salespeople to steer you right.

1. Never walk into a cell-phone store: Stores have poor product selection, undersupervised employees and crowds of angry people complaining about something. Do all your business either online or over the phone.

2. You can get a new phone for free: After two years, Sprint will issue a $150 credit to you for a new handset. Verizon will cough up as much as $100. Cingular and T-Mobile have discounts custom-tailored to each customer, so be sure to ask.

3. Love the Motorola Razr? Sure you do. But users complain about its clumsy user interface and frequent dropped calls. Sprint's Samsung A900 (pictured to the right) is nearly as thin and easier to use.

4. The only department you should be talking to is the cancellation department. Its representatives are empowered to keep you as a customer at almost any cost. They can change your monthly plan, offer discounts and even backdate the savings to previous statements. But they won't do any of this if you don't ask.

What the industry says If you want to watch movies the way they were intended to be viewed, you need to spend as much on a new plasma or LCD as you paid for your first car.

Rebuttal Flat screens are nice, but the real deal to be found is in projectors. For around $1,000, you can get a portable model (about the size of two Yellow Pages) with a built-in DVD player and built-in speakers (many come with an optional external subwoofer). It will display an image as big as any wall or bedsheet, and you can carry it from house to house for on-the-go screenings.

The Verdict Take a look at DVD-projector combos from RadioShack ($800), Optoma ($1,000) and Epson. The Epson MovieMate 25 ($1,200) is a little larger than the other two, but it gives the biggest picture and best sound at close range.

What you'll hear There's only one game in town: Apple. Its iPod and its iTunes Music Store are the absolute best way to listen to downloaded music, and everything else out there is lousy.

Rebuttal Apple's setup is mighty fine, but it isn't for everyone. Parents who worry that their children will bankrupt them with download fees (and don't want to have to deal with iTunes "allowances") may want to consider paying $15 a month for one of the subscription music services. They let you download as much music as you want so long as you maintain the subscription.

The Verdict The best subscription service out there right now is from MTV and is called Urge. It has the latest music, thanks to the network's running knowledge of what's hot.

While you can't use an iPod with Urge, there are some amazing little players out there that are compatible. Creative's cute Zen V was designed to compete with Apple's iPod Nano, and it costs $30 to $50 less.

Best of all, everyone can share in the all-you-can-eat pricing model: Up to five PCs and three players can receive downloads.

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More tips for getting the best deals:

Kitchenware: Cookware, dishwashers, knives

Cars: Navigation systems, pre-owned vehicles, auto repair

Home: Bedding, couches, rugs

Apparel: Dresses, running shoes, suits

Luxuries: Watches, wine, concert tickets, puppies