This article discusses survey data about cell phone use. The results showed that 71% of those surveyed sleep with their cell phone near them. Most have it on their nightstand, but some have it on the bed or even in their hand. The article reports that only 24% of those surveyed keep their phone in a separate room, which is consistent with good sleep hygiene.
I don't agree that keeping your cell phone out of your bedroom is good sleep hygiene. I keep mine next to my nightstand every night. For me, my phone serves as my pager for when I am on call but also as my alarm. The problem with having a cell phone in your bedroom occurs when you use the phone to help you fall asleep, rather than learning to fall asleep on your own. Or if you get texts, email alerts, or calls all night from friends and family - this will disturb your sleep. But just having the phone next to you is not necessarily a problem.