Apparently Penguin books is trying to be new and hip and has a web fiction experiment going on. They've got six authors to write six stories (based on classics it seems) which work with some kind of hypertext gimmick. Currently they're in week 3, althoughI'm still going through week 1, a story called the 21 Steps.
It's a spy mystery thriller which tracks the story along on Google maps. It's a little bit light on the text, and a bit slow moving over the map, but it's kinda interesting. I would enjoy it more if I was more familiar with London and Edinburgh I think.
The second story, Slice, seems to be built on a background of blogs and twits. I haven't gotten that far yet, so we'll see. It looks like there's a lot of backstory, what are blog archives but? The third story is a fairy tale and I haven't even looked at it yet.
It reminds me a bit of Elizabeth Bear's (and others) experiment with Shadow Unit, which is the episode guides, background information, etc etc for a fictional TV series. I haven't been really following it, but it has garnered a fan base. No real surprise, as a SF&F writer she has an inbuilt fanbase who love this kind of stuff. More power to her.