Elementary's default file manager, Files, has single-click to open enabled by default. For those who prefer double-click to open, how can this setting be disabled?
For Freya, apparently installing Elementary Tweaks and changing the setting there works:
apt-get install elementary-tweaks
Then, access the Settings Menu and click on the Tweaks Icon.
You can then toggle Single Click on/off as you like.
Unfortunately, this didn't work for me, and the setting immediately toggled back on as soon as I exited the settings menu.
I had better luck with the following command:
gsettings set org.pantheon.files.preferences single-click false
Newer pantheon-files needs:
gsettings set io.elementary.files.preferences single-click false