How to change the default program for pdf (only for current user)

To set the file associations :

1. Right Click on the file
2. Choose Properties
3. Go to the Open With tab.
4. Choose your file viewer. For eg. acroread.
5. That's it. Click on close.

Also see this answer for an alternative method.

To set the default program to pdf

1. gedit ~/.local/share/applications/defaults.list
2. Add application/pdf=acroread.desktop or application/pdf=AdobeReader.desktop

The correct name of the .desktop file can be found in /usr/share/applications/

This will set the pdf default program as adobe reader

An update for Ubuntu 13.04. I am, however, using Gnome fallback session with no effects.

I wanted to use Foxit Reader 1.1 for my default PDF viewer, but I couldn't add it through right-click in file manager and "Open With," right-click properties and "Open With," or through "System Setting" → "Details" → "Default Applications".

What did work for me was "Ubuntu Tweak":

1. The PDF default is under the "Admins" tab, then click the "Applications Centre".
2. Look for "All" in the "Category" column on the far left.
3. Scroll down to find the "PDF" file type and the "Associated Application".
4. Double-click to change (brings up a window) where you can "Add" an application through one provided or find your own.