In July, I raved about YouTube's innovative mobile "Add to Homescreen" promotion. Eightbit.me has gone a step further and actually requires users to "add eightbit to [iPhone] homescreen". In fact, each time you visit Eightbit.me, you have to add the icon to your phone's homescreen. In other words, if you visit http://eightbit.me on your iPhone, you see the following screen. You cannot advance through the site without adding it to your homescreen.
It's also clever.
And, while dangerous as part of the core site experience, it has interesting applications. For instance, it is well served as part of unique flows. Perhaps a promotional campaign or special reward / unlock is only accessed after adding to homescreen. If measured properly, marketers have the opportunity to incent behaviors measured through downstream efforts (ie Facebook Likes : viral sharing; Tweets : retweets & visits; add to homescreen : repeat engagement).
Of course, the experience itself has to be rewarding enough that users will choose to click on the icon and reengage. Thanks to notifications and increased functionality, applications have easier times driving reengagement... as HTML5 improves and mobile developers innovate, perhaps that changes.
This is a step (albeit not perfect) in that direction.