It's not just games getting into the flow, here're two studies from the literature looking at how best to generate flow in web pages, to optimise browsing and to keep people sitting on consumer websites. Both of these are referenced in Episode 7 of the podcast.
Measuring the Customer Experience in Online Environments by Novak, Hoffman & Yung (1998)
Optimizing Flow in Web Design by Andrew King from 2003
And straight from the horse's mouth, have a gander at a 1996 interview in Wired Magazine with Mihaly Csikszentmihalyi called Go With The Flow.