How do I set which applications I want to be the default?

sry.. wish i could edit titles. :) but this is on a Mac, as the "topics" might indicate.

In the Finder, click Apple-I (Get Info) after selecting any PDF file. From there you select Open With and click "Change All". It's one of the rare poor UI choices in OS X.

Right click or control click and on the open with...toggle it with the option to always open with.

thnx guys! perfect!

Did you mean "Preview" or is "Reader" another PDF viewing app?

"Reader" as in "Adobe Reader" -- the standard PDF .app from adobe (creaters of PDF) - Acrobat, on the other hand, is for both reading and writing PDFs.. but these days there are a lot of other ways to write PDFs and acrobat is just a pain..

Gotcha...agreed Acrobat is a resource hog. I use Preview for all my PDF viewing and Acrobat for editing only. I've found Preview to be much faster and more lightweight than even Acrobat Reader.

ya.. i just don't really like the way preview is set up.. and the controls are a bit archaic.