Shoutbox

this is already possible, as plus saved preferences for each users separately

1) log on msn with your account
2) go to chat log options (plus > preferences > conversations > chat logging)
3) change the file destination to something like C:\Documents and Settings\’user name’\My Documents\My Chat Logs\’your email’
4) click ok and sign out of messenger
5) log on messenger with your brothers account
6) change his file destination to C:\Documents and Settings\’user name’\My Documents\My Chat Logs\’his email’
7) click ok