BookishBabe -- Do keep in mind that "The Colour of Magick" is, in part, built on satirizing other sf/fanatsy traditions and books--a trend that he discontinued shortly thereafter. Like many others, I agree that the first two are not quite as good as the others, since Sir Terry was finding his stride as a writer.
Alareth -- It's alright. You don't need the meeting. Those of us who have to come to terms with the notion that We'll Never Have Another Discworld Book, do. We're the ones who will go through withdrawal. But, better to have loved and lost, etc.
If you want to get some of the flavor, I suggest "Pyramids", which is more-or-less a stand alone book in the same world as the others--and includes the Disc's Greatest Mathematician, a fabulous character.
You other Pratchet-heads, I highly recommend, "Once More...with footnotes" which you can order from England. Also, the new book "Nation" is simply excellent, one of his best ever. And I personally enjoyed the "Bromeliad" trilogy very much.
Don't let me detain you, Miss Kitt