Nokia Beta labs have officially released MUPE - Multi User Publishing Environment - a sort of applications framework-cum-social network thing that makes it easier to create multi-user games and apps.
To use it, you just need to install the (Java) client on your phone and you can then download any of the apps that have been created with the MUPE developer tools. So far, most of these seem to be games, but there are a growing number of social apps like Books and Gathering.
MUPE apps can be location-aware (on supported handsets) and this opens up a lot of interesting possibilities, both for local social-networking and location-based games (Nokia laser tag, anyone?)
MUPE has been available as an open-source project for a few months, but now it has been adopted as a Beta Labs product you can expect more developers to join in the fun.
