Other than actually activating your core (and shooting for intensity over duration), the key to making planks not suck is to keep your mind busy, whether that's lifting limbs, walking around, or moving weights.
This exercise will hammer the trunk when you maintain a rigid plank. And once you've got that down, you can raise the difficulty by increasing the load or moving the weight in front of the hands.
You're punks. All of ya'. All of ya' under 25 or so, that is. Mike Mahler calls you "Generation Ent," for Entertainment, meaning you need to be constantly entertained. Well stand by to be entertained, in a manner of speaking.