Get an expansion card (express card) with Firewire ports
we wanted to use our canon vixia with our laptop to stream live events.
we bought a Express Card with 2 firewire ports (37 usd), plugged it into our laptops expansion card slot, tehn connected the camera to that Firewire port using a Firewire cable.
as recommended we installed Livestream Producer on our laptop, selected the Microsoft DV option for video input and it worked excellent
we noticed the only issue is that it does not support Full HDV trasnmissions, but it is because we are using the free version.
hope it is useful for you. we are starting with this, so we will keep investigating, but we are very interested in mobile live broadcasting.