Scientist still aren't sure about long term effects of mobile phone use, although this is the most recent study reported on, which seem to suggest that long term use isn't as bad as everyone initially thought.
I thought that could be worse as then it would be a bit inside your ear?
Nah the dangers supposed to come from the microwaves that travel between the mobile phone mast and the mobile that transmit your voice and whomever yourspeaking to back and forth.
If you use a handsfree kit, the mobiles going to be futher away from your brain.
i find that i get a really bad headache when i've been on it for something like an hour, and even quicker when it's plugged in on charge.
I used to on one of my older mobiles but my last couple have been better, its because you're brains being vibrated the same as the speakers are to your stereo, or tv when the signal comes in, you know that dug-a-dug-dug-a-dug noise, imagine that being vibrated through your skull instead of the speakers in your house!
I would say its fine. There have been so many contradictory studies, some say it is dangerous and causes cancer and whatnot while others say that the risk is greatly exaggerated. A 1/2 hour a day really isn't much at all anyway but as others have said if u're worried get a handsfree kit.