Shields:
Flame shield, ice shield,
lightning shield, venom shield: Provide corresponding resistances.
Shield of light: Provides light when worn.
Shield of mobility: Provides free action.
Gauntlets:
Gauntlets of force: The wearer, when fighting barehanded, can knock monsters back with great force.
Gauntlets of fortune: The wearer's _base_ luck will be +5.
Helmets:
Helm of discovery: Provides searching.
Helm of vision: Provides blindness and hallucination resistance, protection from shape changers, see invisible, and infravision.
New random description for helmets: Tinfoil hat.
Blocks mind flayers' mental "lock on" attack and monster mage-spell casters' Psi Bolt spell.
Also blocks telepathy from all sources (including itself if it's the helm of telepathy).