Adactio Photoshop Actions is a set of tutorials and downloadable actions for creating various effects in Photoshop, including a Lomo and a painted effect.
Lomoize has instructions for creating a Lomo effect in Photoshop using either a downloadable action or the detailed tutorial.
Okay, that's pretty cool. I love my Lomo, though it's more from the process than ... um. I don't know how to express this. Trying again: I love my Lomo because it put the mystique back into photography for me. But being able to Lomo-ize something is a funky concept.
I think that one of these days I'll see the light and try my hand at actual photography with a Lomo. Up until now, it's been digital pictures of kids and cats, cats and kids. In short, I think I have camera envy.