BBC: Bead 'slashes mobile radiation'
http://news.bbc.co.uk/2/hi/health/4203077.stm
(from BBC)
Ferrite beads are commonly used in computers to stop interference Radiation from hands-free mobile phones can be reduced to virtually zero by a simple tiny magnetic bead which costs a few pence, a government adviser says.




Results of measurements using hands-free kits
http://www.senat.fr/opecst/resume_english.html#fn7
«About forty measurements were carried out at 900 and 1800 MHz, using five telephone models and five types of hands-free pedestrian kits.

The SAR never increased at head level using the pedestrian kit. When using a hands-free kit, the SAR varied from 0.39 to 0.007 W/kg depending on the mobile phone/kit match and on the way they were configured. The average reduction is around 50 times in normal conditions of use, the smallest decrease being twofold (worst case). The effectiveness of two hands-free kits used with the same mobile phone and in the same conditions of use varies from a factor of one to a factor of ten».