This has been percolating round the blogosphere (eek!) in general, but ARGN has an excellent summary of possible 'alternate reality game' LonelyGirl15 - well, ARG, or prank, or advertising campaign, or something?

ARGN explains: "The white-hot spark of a YouTube user named LonelyGirl15 has set the dry timber of the summer internet community ablaze. Ostensibly the video blog of a teenaged American girl named Bree, the 23 videos posted so far have chronicled a budding romance with a boy named Daniel, but there's a twist: Bree's family is very religious, she is home-schooled, and she has pledged a "purity bond" with her father."

It generally gets odder from there on out, and there's been plenty of detailed speculation into the phenomenon, which isn't a 'video game', by any stretch of the imagination - but is a great example of interactive storytelling using the Internet, which is why we're linking to it - besides which we tend to cover ARGs, and this may yet be one. Or not.