It’s still in beta, but what isn’t in beta these days. It’s pretty useful to maintain you’re msn-account when you don’t use msn messenger (the client) but for instance something good like psi. ;)

Anyways it’s like summary says, you can use it on any shared computer - at school, at work, at a friend’s house or anywhere you can’t, or don’t want to install the MSN Messenger software.