I just posted my first vim script, a syntax file, to vim.org: http://vim.sourceforge.net/scripts/script.php?script_id=3038
It is a little mode, of sorts, for working with Noweb files in vim. Basically, it uses one syntax for the doc chunks, another for code chunks, and autofolds the code chunks (off by default). Folding just feels natural with code chunks. I am using it now with one of my tinkering projects and, despite its minimal size, a mere 35 lines, it is really nice.
Of course, it would be a little odd to write some code to facilitate literal programming in a nonliteral style. I will be posting the full literate version here, shortly.