Something a bit different:
Ring of cardboard. It turns the wearer into a cardboard cutout of himself, allowing him to slip through unbelievably small passageways, under doors, and the like. Have it make you slightly harder to hit while making your hitpoints go down while wearing it.
Rope of ropeburn. Regular rope, but anyone not in the owners party gets hurt if they try to climb it or touch it. If you use it to bind someone it only hurts them if they move. Probably better to make it _small_ amounts of (fire?-) damage, so it doesn't get overused.
Book of weather. It has pictures of different types of weather on each page. Reading the description makes the weather assume that of the image. Each image can only be used once, and then the image fades away.
Rock of ruined water. If you squeeze it, water comes out. Higher strength gets more water. The water smells horrible, and chases wildlife away. If you boil it, it becomes drinkable.
The spyglass of gossip. Looking through it makes you able to hear what the targets are saying, but it alters the conversation slightly, just like real gossip.
Boots of different terrain. They make you walk on water as if it was sand, sand as ice, ice as rock, rock as (deep) snow, (deep) snow as grass, grass as water (the character will need to swim through the grass).
The sundial necklace. A necklace with the picture of a white sun. It has a small dial. When you turn the dial the light of the actual sun turns to wherever you want. Only works during the day, but works in any weather. Essentially it makes the sun your personal flashlight. You can use it to (really) light up a stormy night, or temporarily blind an opponent, or whatever inventive the player comes up with. Once per day, small duration.
The necklace of the way. If the character has already been somewhere the necklace can show him and the party a shortcut that is twice as fast. Even if such a shortcut was otherwise impossible.