i dont know if this is what you are looking for,  but will give you a rough idea of whats out there. This will work best with a clear line of sight to your nearest base station . You can use then with a 3G/modem with external antenna port 


http://cgi.ebay.co.uk/3G-UMTS-20-5dBi-antenna-20M-wire-HUAWEI-E176-E156G-E169-/370480382291?pt=UK_Computing_LaptopAccessories_PCMCIACards&hash=item56425a0153#ht_18406wt_910

http://cgi.ebay.co.uk/Antenna-UMTS-3G-PANEL-MAX-Huawei-ZTE-4-m-cable-/260671329061?pt=UK_Computing_Networking_SM&hash=item3cb138d325#ht_1866wt_932

http://cgi.ebay.co.uk/GSM-Antenna-900-1800-Mhz-Directional-24dBi-3G-data-/230601420122?pt=UK_Signal_Boosters&hash=item35b0ea6d5a#ht_3831wt_1141


On 29 April 2011 08:13, John Doe Smith Kamau KipNg'etich Jones <skunkworks.ku@gmail.com> wrote:
hi skunkies,
.... thanks to all the flats cropping around my home, my 3G orange
reception & quality has dropped drastically ovet the past few
months...

any of you know where i can get some elaborate 3g gear.... perhaps a
modem that comes with an external antenae.... just anything to boost
that 3g signal?

cheers
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