How to show hidden files/directories in Firefox file chooser?

[Mario Vukelic]

On Wed, 2008-11-12 at 17:01 +0000, Chris G wrote:
> How do you get to see hidden files in the Firefox 3.x file chooser?

In addition to my other reply just now, there is a third one:
Type a dot in the location bar and press the Tab key. Pressing tab after
entering an incomplete filename (or command) has been standard behavior
for decades and is really helpful also in other situations (also works
in the command line shell)