The name says it all: Hand Grenade Sword Cane. All it needs is a sniper gun attachment of some sort and it will probably be the most lethal walking stick on the face of this planet. Granted, the grenade won't actually explode and the only way you could impale someone with that 'sword' is if you spent hours sharpening it first.
The best part about the Hand Grenade Sword Cane is that it's only $30! Sure, it is mainly just a cane, but if you did pull the pin on the grenade it would reveal a handy compass.