Code:
alias mouseidle {
  if (%idlemouse.x == $1) && (%idlemouse.y == $2) && (!$away) inc %idlemouse.count
  if (%idlemouse.x != $1) && (%idlemouse.y != $2) && ($away) { echo -a you're back! | away | unset %idlemouse.* }
  if (%idlemouse.count == 60) { echo -a you're away! | away GONE!!! | unset %idlemouse.count }
  %idlemouse.x = $1
  %idlemouse.y = $2
}
on *:CONNECT:.timeridle 0 1 mouseidle $!mouse.x $!mouse.y


Just something I threw together quickly. The timer is set when you reconnect to a server.

You won't like it when I get angry.