"[To improve my Airport reception] I was next instructed to eject the battery and look at the right side wall of the battery compartment where I was supposed to find an approximately 5 cm long plastic strip. (My particular powerbook doesn't have this visible -- instead, there is a plate with the serial number, etc...) Still, he told me to firmly press the side wall of the powerbook against the frame, just slowly and firmly pressing along its length several times for about 10 seconds. Next, he told me to replace the battery and start her back up.
I can't believe it, but my Airport's range is now like my iBook's!! I never could have done this from out here by the pool before, but here I am.
The reason for this as he explained it is, where I was told to press is where the antenna runs alongside the framework of the Powerbook. Sometimes it isn't situated just right, or gets out of whack from having been shipped or something. Pressing it puts it back into proper contact with whatever needs to be touching."
If your reception is still unsatisfactory you can purchase a wireless card for your PCMCIA card slot.