Here I use 2 linksys wrt54g-tm wireless routers to extend wifi internet to my backyard, pick nick table.
Using several routers, modified with DD-WRT firmware configured to run as wifi repeaters.
I am able to boost a weak wireless signal
from inside, even a brick building. The antennas used are linksys oem although high gain antennas from after market sources are availible.
The wifi signal from a host router to a hacked T-MOBILE wrt54g-tm is repeated to a third linksys router with the same modifications to the firmware.
The umbrella antenna is just a way to get the router further from my laptop, and is of no use to the signal boosting qualities of wifi power increase hack.