Inspired by yesterday's ImageMagick trick and my curiosity as to how to accomplish the LOMO effect using Mac OS X graphics primitives, I whipped out Quartz Composer and cobbled together a simple pipeline:
The file is here, and you need the Developer Tools installed to do anything useful with it (it's actually somewhat of a non-accomplishment, since it does not do anything on its own).
I'm pretty sure this can all be rolled into a single OpenGL patch, but it's been years since I did that sort of thing and this is, after all, probably the first thing I created from scratch with Quartz Composer (plus it was kind of relaxing fiddling around with the settings and trying out different combinations).
If I have time (not bloody likely, at least for the next week or so), I'll try turning this into an Automator action (never bothered to read the documentation on that, haven't the faintest idea of how tricky it will be).
As a minor exception to the CC license that governs this site, anyone who has the time and know-how to do it themselves is free to use this as a basis for free Automator actions (I've seen a lot of pretty crappy stuff being peddled for cash).