You can also format source code like this:

    #+BEGIN_SRC bash
    $ echo Hello, World!
    #+END_SRC

That will also give you syntax highlighting, and allow you to edit it as a bash script (in Emacs, at least).

I don't remember it off the top of my head, but there's also a similar syntax to include a file directly, instead of duplicating it in the org file.

#+INCLUDE

In Emacs, <s + <TAB> at the beginning of a line starts a source block. The delimiters are quite distracting though. This is an issue I have with markup languages in general, either you use markup very sparingly or the document easily becomes unreadable.

And you can customize it too! In the past I have set up <r to create an R source block with some common code block parameters for R.