Using Firefox 3 on a Mac in conjunction with the firefox-mac-pdf plug-in, you can finally view PDF files in Firefox without having to open Preview. While Preview is a great app for looking at PDFs, it takes longer to view PDFs this way in the browser since you have to wait for the external application to open. This has always been one of my dislikes about Firefox on the Mac. And while it's still not fixed in Firefox directly, this plug-in in does provide the ability to see PDFs directly in Firefox seamlessly.