MDK : Quicklook for markdown
http://www.mdk.org.pl/2009/2/10/quicklook-for-markdown
View digital comic CBZ files using Quicklook
http://www.the8thsign.com/2007/11/19/view-digital-comic-cbz-files-using-quicklook
"Digital comic files come in two flavors, CBZ and CBR. They are just renamed ZIP and RAR files containing JPG files."
Quick Look from the command line! at srhaber.com
http://www.srhaber.com/2007/11/04/quick-look-from-the-command-line
"For all you Leopard users out there, here’s a handy trick to use Quick Look from the command line."