PDFs seem like a good thing to some people, where other folks put them in the same level of Hell as Microsoft. My opinion? Yes!
The main beef I have with PDFs stems from coporate control. Only one company (Abode) controls the PDF file format specification. Single control has traditionally been a precursor to Evil; sooner or later the entity in control makes a decision that is good for the controller and bad for many others. And the others lose, as they have no way of influencing the controller.
So why in Earth would I use PDFs on my very own site? Simple: PDFs do have a valid purpose for the web: Format Control. Yes, PDFs can be used for evil (see javascript support and maybe you'll figure out why), but until a decent open document format is out there or HTML can be used to both print a decent looking piece of paper as well as on the screen WITH A MINIMUM OF EFFORT, PDFs fill a minor role.
So, since I'm too lazy to maintain a document in two different formats manually, I will occassionally use PDFs. The important difference is I try to use a PDF format that most people will be able to use. So if any of my PDFs can't be read, please let me know and I'll try to accomodate you.
wkks.org -> Bill's Room