For example a group like Third Way might decide that something they posted is a bit embarrassing and want to make a few quick changes to limit future damage. Sadly if you haven't preserved a copy for future reference you are out of luck.
Any Penguinista knows this is an easy chore on the command line with "wget". Now wget will not make a copy of the website that perfectly matches the original's layout however it will drag down every document on that website and store it on your local system for safe keeping.
For those experienced with working on the command line the command is simple:
wget -mk http://www.thirdway.org/
This command will create a directory that has the name of the web site, in this case www.thirdway.org, in the present working directory of your shell. The time it takes to make the copy will depend on your bandwidth, the speed of your system and that of the web server.
For those unskilled with the command line you can simply open up your home folder on your desktop then go to File and select "Open in Terminal". In the shell that is created type in the command above. If you feel the need to organize things a bit create your directory structure and select the directory you want to hold the web site then go to File and click "Open in Terminal".