I usually spell it Plyometrix, its less letter and goes along better with the X mentality, but either way.
P90X Plyometrix is basically an hour worth of leg work and cardio.
The warm up is a bit different than the resistance warm ups, there is a long series of lunges in the warm up, along with all the regular warm up stretches.
Plyometrix is probably the toughest workout in the P90X program. You do a series of 4 moves. The first 3 moves are for 30 seconds, the 4th is for a minute. Then the sequence is repeated. After it is repeated, there is a 30 second break.
Here are some of the moves contained in Plyometrics (in no particular order)
Run Stance Squat Switch Pick Up
Rock Star Hops
Jump Knee Tuck
Double Airborne Heisman
Leap Frog Squats
Once you finish this workout, you will be sopping with sweat. The tip to use some Recovery drink during work out is not a bad one at all.