graeme_p - 5:04 am on Dec 4, 2012 (gmt 0)
The Nautilus preferences are available in the GUI (well in 12.04 Precise, anyway). Preferences > Behaviour.
There is a "show hidden files" in the right click menu in the GTK file chooser. Its obscure, but its better than a Mac (because the key combination that is supposed to do it, does not seem to work)
Do you really need to reboot? Logout and login at the most, surely.