Jean Pierre pointed out a fabulous little extension for Firefox 3 on OSX:

The firefox-mac-pdf extension embeds PDF files right in the browser, so you don’t have to download them, open them with Preview.app and remove the file off your desktop afterwards. It works much like Acrobat, except it uses OSX’s built-in PDFkit.
That’s definitely an extension I’d like to see on AMO.
As Adobe’s James King has blogged yesterday, the PDF format (in its version 1.7) has just become an ISO standard (number 32000). The final standardization document is expected to be published in early 2008.
Almost a year after the work on the standardization has started, the ballot was passed yesterday with 13 vs. 1 votes. The only country to oppose the motion was France, and Russia abstained.
PDF as an open standard: For the file format landscape, I believe this is a good move. As members of international teams have already known for a long time (at least since the Tower of Babel), you can only really work together if you speak a common language. Standardized, open file formats are the common language of the internet age. Now, PDF is in good company, along with the Open Document File format that has already been standardized in 2006.