I read asa's acrobat reader 7 recommendation, and I have to agree: download Acrobat 7 (Windows). It's way fast (or rather, its not way slow like Acrobat 6, which horribly froze my browser for up to a minute).

I just tested it out on some paper links and it removes my chief complaint with pdf -- that it breaks the browsing experience by making you consciously aware that a plugin is loading due to its abundant slowness. As an added benefit, there's no stupid slash screen on startup.