Gentlemen, I present to you the most stupid weapon ever developed in WWII... The only other weapon that could be worse is a nuclear handgrenade.
The M-388 or "Davy Crocket" is pretty much a short range (as far as nuclear weapons go) nuclear RPG. I had the pleasure of seeing one of these bad boys when I visited the Aberdeen Proving Ground Ordinance Museum in Maryland. It has a maximum range of 1.24 miles or 2.29 miles, depending on what version is in use. The bad part about this thing is the two man crew that fired it were well within the blast radiation range. They were hit with 350rem of radiation. A man can be exposed to roughly 700rem of radiation in his lifetime before fatal results. The crew couldn't shoot it twice. I don't know if they were ever used in the war, but they were planned to be used against the Soviets.
All this information that was taught to me by... man I wish I could remember his name... a WWII weapons expert who is frequently asked to appear in shows for the discovery channel. Anyway, he makes his home at the Aberdeen Proving grounds Ordinance Museum.
If anybody lives near DC or Aberdeen, I highly suggest you go to see the Ordinance Museun. They have almost every weapon in use during WWII. Everything from the Davy Crockett to the bent barrel MP40 for shooting into tanks.