RIP-OFF ALERT: Are you old enough to remember the days when an entire metro area had a single area code? Over the last 10 years, legions of new area codes were implemented across America. It got to the point that you might not even recognize all the area codes in a given city.

That ignorance actually creates an opportunity for criminals.

Here's what's going on: Scamsters will call you and let the phone ring once. Most folks have cell phones or caller ID on their landline or business line, so if they miss a call, they'll simply call the number back.

Bad move. Many international locations have similar area codes to our domestic ones -- even though they're not based in the United States. So that callback can trigger massive fees.

So how can you protect yourself? First, don't respond to any number you don't know. If it's an important call, they will leave a message. Second, you can block international calling with most cell providers and landline providers.

But you shouldn't expect a lot of help from your phone provider on this one. They make a cut of the action by splitting the revenue with whatever overseas phone company that handles your call.

Meanwhile, you may recall that Clark's been talking a lot about Boost Mobile, which offers a $50 unlimited cell plan (including junk fees).

In just 90 days of operation, Boost has signed up nearly 800,000 new customers, according to Fierce Wireless. Boost's competitors were no slouches themselves during the same period. Metro PCS added 700,000 customers and Cricket added 500,000.

Partly, they're all gaining customers because of the recession. But don't overlook the fact that each one offers a better deal than the traditional cell phone players.

In fact, the bigs of the cell industry are fighting back against these smaller outfits. For example, AT&T has a new pre-paid unlimited calling plan where you pay $3 for each day you use the phone. No roaming and no long distance charges. It's a good option for an occasional on-demand cell phone.