I thought I'd add that COC mines use a weird system to sim shrapnel, but when I thought about it, it seemed pretty good. In my expierence, when the mines go off a bunch of bullets are camcreated in a circle and then radiate out like ripples on a pond. Not very destructive, but a good sim.
Otherwise, I like ECP or reg BIS (even if they go off on contact) grenades. But in gameplay, I usually don't care, its one of those "just chuck the damn thing!"...
White phosphouros (can't spell) could piggyback on some scripting I saw for napalm. Just change the drop effect.