changing default file associations in gnome 3
How do I change the default file associations in F15/gnome 3? My system is currently set to open .tex files with emacs. But I prefer TeXworks, and while TeXworks shows up in the "Open With" menu, it would be convenient if double-clicking on a tex file opened it in TeXworks. In gnome2, the "Open with-->Other application" option let me select the default program associated with a particular type of file, but this functionality seems to be gone in Gnome 3. Do I have to edit some config file?