How to make an offline mirror or duplicate copy of a website using wget

Sometimes you want to create an offline copy of a site that you can take and view even without internet access. Using wget you can make such copy easily:

wget --mirror --convert-links --adjust-extension --page-requisites --wait=2 -o log --no-parent http://example.org

Explanation:

--mirror // Makes (among other things) the download recursive.
--convert-links // convert all the links (also to stuff like CSS stylesheets) to relative, so it will be suitable for offline viewing.
--adjust-extension // Adds suitable extensions to filenames (html or css) depending on their content-type.
--page-requisites // Download things like CSS style-sheets and images required to properly display the page offline.
--no-parent // When recursing do not ascend to the parent directory. It useful for restricting the download to only a portion of the site.
-o foo // write "log" output to a file named "foo"
--wait=seconds // Wait the specified number of seconds between the retrievals.
// Use of this option is recommended, as it lightens the server load by making the requests less frequent.

Alternatively, the command above may be shortened:

wget -mkEpnp http://example.org