SLIPPYSLOPE  I learned of AP Grapher on the Apple Discussion board dealing with the MacBook Pro dropping Wi-Fi connections. Grapher is a great way to track connectivity and confirm that there is a 'drop' even though the Mac 'Radar' says there is a strong connection. Grapher worked perfectly right from the getgo on my MBP Intel Core Duo 2.16 GHz running 10.5.2 (and now I have the evidence that the MPB is dropping the connection). Thanks.  
(Version 1.2.1)