Many people can't imagine life without their cell phone. But now the World Health Organization is suggesting there might be a link between cell phone use and cancer. And that's causing millions of cell phone users to consider dialing back on usage.

There are 5 billion cell phone users in the world today. Cell phones have become a key part of life for many.

So, the recent suggestion by the World Health Organization that cell phone use might increase the risk of brain cancer left some people pretty rattled.

Colleen Bartlett, cell phone user said "If there is some sort of link, I absolutely think they should bring it to our attention and we should change our behavior, but there's not enough talk about it."

A working group of 31 scientists from 14 countries gathered at a WHO meeting said a review, not new findings, of all available scientific data suggests cell phone use should be classified as possibly carcinogenic and suggest consumers consider ways to reduce their exposure to cell phones.

Not so fast, according to Dr. Philip Stieg, Chair of Neurosurgery at NY-Presbyterian/Weill Cornell.

Philip E. Stieg, Chairman of Neurosurgery, NY-Presbyterian/Weill Cornell said "The most recent study produced in 2010 suggested that there was no inherent risk in using cell phones and the development of malignant brain tumors so I think people need to take a step back and relax and realize that number one the recommendations are only possible carcinogen and not a definite carcinogen."

Stieg says in the absence of definitive evidence linking cell phones to brain tumors - he suggests people continue to use their cell phones as they are. But some consumers offered ideas on how to limit exposure to radio frequency waves...which includes talking a bit less.

Michelle Siegel said "We could still get by with texting rather than phone calls and just use house phones for phone calls."

George Serrano, Cell phone user said "They say use a headpiece, a wireless headpiece."

Judging by the word on the street...the WHO recommendations aren't strong enough to limit cellphone sales. Gartner reports 428 million mobile communication devices were sold in the first quarter of 2011, a 19 percent jump over the same period last year.