8! Count 'em!
If anyone has seen or know quite well this type of experiment, one can truly appreciate what a feat this is. It appears that physicists in China has managed to entangle 8 photons and set a new record. Ars Technica has a good coverage of this accomplishment, in case you missed it. It even listed the "straightforward" steps in achieving the 8 entangled photons. But don't be fooled by such a simple-sounding list. It isn't easy!