Cursed items in the typical D&D sense don't quite work the same as they did in PnP games. A common way that cursed items would manifest is that you could not put them down. Cursed armor could not be removed, for example.
(side note: we had at least one character who donned cursed armor and could not remove it until the curse was removed. This was, however, an RP restriction not enforced by mechanics)
My favorite were cursed, intelligent items that stood the chance of taking over a character, either permanently or under certain circumstances.
Anyway, to do cursed items justice, it introduces some overhead and requires custom scripting, as NWN doesn't really implement the "cursed" property very well.