As the title says, I'm suggesting a new idea for an item: lamps.

I can see six types of lamp that could be implemented (as tools).

1. Regular lamp. 'U'se it in the same manner as a torch (requires flint and steel, but not tinderbox), but these do not disappear when used up. Can be "recharged" using a potion of oil (Undecided on whether you dip it in the oil or 'u'se the oil), or to a lesser extent using a potion of booze.
2. Self-lighting lamp. Much like the regular lamp, but does not require flint and steel - basically, it has a built in lighting mechanism.
3. Permanent lamp. This lamp is always on when in the possession of the PC, cannot be extinguished. Rare. Useful if the PC wants a light source, but troublesome if the PC wants to cast/use darkness. Cursed permanent lamps would drain PP.
4. Faulty lamp. This lamp, on being lit, will explode in a fireball in one turn (with the extent and power of the explosion being dependent on the amount of oil in it). Can be used as a kind of grenade, providing an effect resembling Improved Fireball if lit then thrown. If not thrown, it will explode in the PC's possession, doing fire damage to the PC and any being around the PC, which could be useful if the PC has strong fire resistance/immunity and doesn't have any important items in inventory that are vulnerable to fire (or has ring of ice and fireproof blankets), and is surrounded by foes.
5. Lamp of darkness. This is a kind of inverted lamp, allowing the user to essentially create darkness instead of light around the PC. Might perhaps react badly to an amulet of light.
6. Djinni lamp. Maybe a new artifact, or maybe just a very rare item. Will grant up to three wishes (if artifact, independent of B/U/C status, if just rare item, then only for Blessed status). Lamp disappears on use of all available wishes (unlike ring, which turns to a brass ring). Could perhaps (if not an artifact) come in two flavours that are indistinguishable by unIDed or IDed name, only distinguishable by Greater Identify - Good Djinni lamp and Evil Djinni lamp. Using the Good Djinni lamp grants wishes, using the Evil Djinni lamp summons a hostile Djinni; result independent of B/U/C status.

Unlike Torches, Lamps wouldn't be useful as a melee weapon. They would be heavier than torches (say, 20s), and the ordinary burning lamps (1 and 2) would tend to have fewer turns by default than your typical torch, with the upside being that they are refillable. Could perhaps also be made of a metal that is immune to fire damage.