Mac OS X: Show / Hide files in Finder

I always forget how to do this and have to read back through my notes or look it up online.  By placing it here I can easily look it up and also list it for other people to see.

These commands are run from the Terminal app, found in ~/Applications/Utilities.

To show hidden files in the Finder, type or copy/paste the two lines of text below, pressing enter after each line:
1. defaults write com.apple.finder AppleShowAllFiles TRUE
2. killall Finder

To hide hidden files, paste these two lines of text:  (This is the system default)
1. defaults write com.apple.finder AppleShowAllFiles FALSE

2. killall Finder

If you have hidden files set to on or off, it will remain that way even after reboots until you change it again.  There are no adverse effects from running these commands.  If they were dangerous you would probably need to log in as root before running them or a password window would pop up.

Here is a screenshot of both:

Launching Terminal:

Showing hidden files:

Hiding hidden files: