I personally wouldn't be too concerned about any amount of radiation reaching my feet; heck, you could roast my feet red and I'd probably be thankful for the extra warmth and color..
OK, true enough I wouldn't want to affect any white blood cell production in my "long" bones, but I'd be more concerned with radiation to my chest and head areas. Even there we're at the same stage as astrophysicists are with "dark matter", putting in an unknown place-holder in the belief that we can some day put in a functional mechanism for the effects we see/fear. Truth is, cell phone radiation just isn't powerful enough to affect human biology through any of the mechanisms we presently understand (heat, chromosomal damage, ion channel interference, electrical signal propogation, etc.).
Towards the end of doing something productive, when my brother comes back from out of town I'll try to borrow his radiation detector. This is one of the $1,000+ true-meal-deals used by his company to measure the strength of electromagnetic signals across a wide range of spectrums (they work in radio licensing). I last borrowed this device when we moved into our present house (directly behind some of those high-voltage lines, coincidentally enough
) and it proved very informative to see how the signal intensity varied not just by location, but by orientation of the receptor/antenna. Perhaps within the week I can get a better read on the electromagnetic field levels found within the LEAF.
Now what were we talking about?? :?