Project Doomsday is my attempt to catalog some of the more awesome and obscure doomsday weapons. Yes, I know that some of these don't actually fit the "doomsday" qualification (killer dolphins, I'm looking at you). I haven't finished most of these articles, I'm just not entirely sure which sources I want to include here.

BEAR (Particle Beam)
The Cetacean Intelligence Mission (Killer Dolphins)
Pluto (Nuclear-powered Missile)
Blue Peacock (Atomic Land Mine)
The W54 (The Smallest Warhead)

Unexploded Munitions:
Unexploded munitions, while not large-scale, are particularly terrifying because they make daily life dangerous long after bombing or even conflict has ended. The BLU-97 in particular made the news a while ago because it was easily mistaken for food packets.
BLU-97 (Cluster Bomb Submunition)
BLU-43 (Liquid-filled Land Mine)