As a side note for this discussion, I think Jeff's doing a great job of explaining how transmission line theory works...
For those that want to dive in a lot further (e.g. Do the math), the ARRL Antenna Book has a whole section dedicated to this topic, and it's written well enough that a mathematical dolt like myself can still follow the concepts and not scratch my head at the math. Too bad the book is something like $70 bucks... I won my copy as a door prize at a hamfest or I'd have never bought one... the book is definitely worth the "price of admission" and the CD along with it contains some useful tools that just add to the value... Nate WY0X