Was in Fiji for a couple of weeks and would have had it every night with the locals. they get the actaul root of the plant and soak it in water for a while and you drink the water. Tastes like shitty dirty water, but its awesome, makes your mouth completly numb when you have enough.
We were having Kava with the locals and having vodka at the same time most nights and then when we got back a mate found on the internet that having alcohol and kava is the worst possible combo for your brain and liver....so i recommend you dont do them together. But hell, we had a great few weeks.
A+ Recommend.