I started using my cell phone for internet connection years ago and delt with crappy signal strengths. A cell phone seller turned me onto this source for external antennas that connect to your phone or wireless card:
http://cellantenna.com/index.php?id=glass
Even the cheap, suction cup attach model more than doubled the signal strength at times. They have more db gain antennas that attach via magnetic mount that could be put on a pole or something.