With a handy cell phone, you can call and be called anywhere you are as long there is a signal. However, I have been receiving unwanted calls – particularly from telemarketers and prank callers. It's so annoying answering these callers. So, I don’t answer calls, whose numbers are not in my phonebook. But, some of them are valid calls.
I wish there is a service here like the PhoneInfoTracer.com, which is available for telephone and cell numbers in the United States and Canada only. The reverse phone lookup of PhoneInfoTracer.com would help you find out the caller’s name, address, carrier, and some details even if the number is unlisted. With these data, you would know what call to answer the next time the caller dial your number. It is also useful in tracing the unknown number that appeared in your billing.