I just found this site:
http://www.wilsonelectronics.com/ListProducts.php?Type=11

They manufacture cell phone power amplifiers. They can pump out up to three watts of raw, untamed cell phone muscle (about ten times the power of a small cell phone). They cost in the $250 to $350 range, though (you can froogle the model numer for prices). Not too much cheaper than a PLB, but still pretty neat.