Hello,
I searched the forums for topics on using the DG1394 firewire grabber and havent found anything. So I figured I'd post a bit of info since its the best/fastest way i found to use live input.
http://www.theimagingsource.com/en/products/converters/
I have been using the firewire one for 3 years and never had problems with it, so its very stable also. A bit expensive but worth every penny.
m.