This fits in with the CIG presentation last Saturday by Jo Ann. Interesting reading.
However, I have to disagree with Dick just a little. I use Adobe Reader and Acrobat all the time and while there are issues with security, they can easily be fixed. Refer to my blog entry last month about security fixes for Adobe Reader. You can easily change your preferences in Adobe Reader that will open a new pdf file in a new Adobe Reader window rather than your web browser.