You either worry about SAR or you don’t. SAR stands for Specific Absorption Rate, which is the unit of measurement for the amount of RF energy absorbed by the body when using a mobile phone. I don’t think about it very often, but once in awhile it crosses my mind that I probably should not use my phone as an ebook reader. I mean better safe than sorry right? Heck, I don’t even know if radiation is an issue when you’re not using the radio part of a phone. If you’re the worrying sort or just want to be informed, then you should check out the Environmental Working Group’s site. Their research team has assembled an online consumer guide to cell phone radiation, rating more than 1,000 cell phones marketed in the U.S. With this free, online tool, you can make informed decisions about which cell phones to buy. The EWG guide uses easy-to-read graphics to illustrate each phone’s radio frequency emissions.