Hey Scott, this is the hacky highlighting I did with code snippets in showoff.
Refer to http://i-dont-trust-your-code.heroku.com/ for the presentation and http://github.com/jtrupiano/i_dont_trust_your_code for the code.
In this first example, I am successively highlighting lines of code from a source file. Refer to slides 22-28 in the presentation and 2-environment/3-custom-require.md in the source.
In the second example, I am highlighting lines of code from irb and shell sessions. Refer to slides 6-13 in the presentation and 2-environment/1-environment.md in the source. What I'd really like to be able to further do is highlight individual results from the ls commands on slides 8 and 10, but that was going to be even hackier.
I'm curious if you would have done this differently. I suspect that this may require modifying markdown itself to get a cleaner way to do this. Although perhaps we might be able to preparse $$$highlight me$$$ out of any blocks that would get interpreted as code? I'm not too sure...haven't really dug much further into it at this point.