What has always intrigued me about the Disc World novels is that there are so many underlying different meanings which are open for interpretation.
I would find it interesting to read your views on what you think a certain book is really about.
I'll start off.
Ankh-Morpork: Synonym for New York or London?
If anyone has read 'Going Postal'
The battle between the normal post and e-mail and evil IBM as the Grand Trunk
Wyrd Sisters: Hamlet?