Hi there :)
Since networks and IT is my main area of interest I can throw my 2 cents.
First of all lets describe WiFi technologies used nowadays
Wifi is a common term used to describe wireless networks based on spec nr 802.11 A/B/G/N
It is used in APs ( Access Points ) to provide wireless connection to clients such as laptops , notebooks , desktops and client routers.
802.11 A - uses frequency band 5.3 GHz
802.11 B , G and N uses frequency band 2.4 GHz
99% of modern laptops/notebooks/netbooks has built-in wireless card which acts like client to Access Point.
Most of them uses 802.11 B/G/N specs which simply means that we are surrounded by 2.4 GHz field all the time.
Even if you dont use wireless connection , your built-in card , in most cases , is turned on and that card is constantly looking for AP which means that it is sending
"search" frames all around laptop and while in this "search" mode its power is maximised.
In addition to that , we have high-power wireless site-to-site links which are used by ISPs (Internet Service Providers) to connect endpoints of their network bus.
And believe it or not but a friend of mine tried to boil an egg by putting it 0.5m in front off high-power directional wifi antenna .... and he succeed :/
IMO there is no way to run away from these WiFi waves unless you close yourself in Faraday Cage like Cs suggested.
You have it in your laptops , notebooks and all around in your neighbours houses. Its just VERY common.
Try sniffing wifi traffic with special software and you will be really surprised how much networks you can discover - if anyone is interested then i can supply direct links to software.
Now to GSM and rest of technologies.
Nowadays mobile networks are entering so called 4G age.
2G - GSM second generation mobile phone network and it uses depending on country bands ranges like 900MHz , 1700Mhz 1800MHz 1900MHz
but there were developed other technologies over a time like:
2.5G - which is 2G plus GPRS - i dont want to go into details but thats the first one that provided internet over mobile phone
3G - UMTS - another better internet delivery technology
3.5G - that is the current one with all that HDSPA HSUPA and other crazy protocols which without going into details means faster interent access again.
Now , that USB stick that Ark mentioned is not a common WiFi. It is just a standard USB "mobile phone" without a keyboard.
What I am trying to say is that USB wireless sticks that work like many adverts say "everywhere" , are nothing else but 3.5G Mobile Phones.
Its not the same as WiFi but a lot of users confuses it with 802.11
WiFi is a short range (aprox. 1-400 metres ) network that wil require AP connection.
So we are surrounded by 2.4 GHz , 900 MHz and 1700-1900 MHz bands.
I was thinking about device that could send an counter wave to above mentioned one but its really not a cheap solution. I am not giving up thou :P when Ill think something out Ill let you all know :)
Ok , so i started to think about whole EM shield thing today.
I was talking with a friend of mine about bioenergotherapeutist ( i hope its proper spelling/name :) ) and he told me a story when his parents asked for a help of one. They had a problem with sleep in home and according to many stories its caused by so called subsurface water rivers/flow. There is an old method to search for subsurface water flow and I know it from older people in my country , because they used this method to search for a place where well could be planted.
They used a tree branch which reacts to EM field caused by water flow. And at that moment i realized that I know another dot. That dot is about cats. There is old practice passed through generations that if you take cat to your home and notice where it sleeps , that will mean that you shouldnt put a bed there beacuse there will be subsurface water flow which cats like and its harmful to people. And another point that could confirm that cats like EM fields is that very often you can find them sleeping on TV (not LCD ones thou )
So I was thinking about it , and came with an idea that maybe it is caused by cats fur ?!
Cast has a lot of tiny hair which could induce static electricity.
And all of sudden it hit me.
Maybe hair is our natural protection against hostile EM field ?
I mean , why do we have most of our hair on our heads ?
Then i realized ( beacuse i lost almost all of my hair from my head recently - candidia ) that our life style causes it.
I mean fast foods , beer and alcohol in general causes fungal overgrowth which in turn causes , like in my case loss of hair and at the same time causes lack of defence against EM field if I am correct.
What do you guys think about it ?
ps2. sorry for poor english