Every cell phone owner has gotten the call: A telemarketer delivers a rehearsed sales pitch or an unprompted recording asks the caller to dial an unfamiliar number.

They're annoying interruptions, but what many don't know is that they can also be costly-to both the caller and a third party.

In one scam, consumers receive a message telling them to call a phone number with an 809, 284 or 876 area code in order to collect a prize or find out information about a sick relative. If consumers dial the numbers, they can be charged more than $25 per minute for calling what is actually an international number in the Dominican Republic.

Similar scams are currently being perpetrated by sex phone operators.

Brownsville's Gladys Porter Zoo was struck by a text message scam earlier this year in which thousands of people around the country were asked to call the zoo about an unnamed emergency. Although callers were charged normal rates for the phone calls, the zoo was forced to shut down its phone lines for nearly a week, affecting several scheduled events.

"Call now, someone is looking for you," one message read.

"Call now and we will settle this," another said.

The Federal Communications Commission asks the victims of such scams to file a complaint on its Web site.

"Trust the source of information you receive," said Joe Farren, assistant vice president for public affairs at CTIA, a non-profit representing all sectors of wireless communications.

AT&T echoes the suggestion that callers return calls to familiar numbers only and carefully read their telephone bills.

But as cell phones become more and more commonplace, FCC spokesman Matt Nodine expects that telemarketing scams will become more popular on cellular devices.