[SixOfSpades]

For some reason, the vast majority of Cursed items are found in the Underdark, which is strange since most of them could have been carried with the party in the transition from BG1. Whether they came with you or somebody else is open for debate, but one must postulate some unfortunate person(s) who got stuck with most of the Cursed items in the Sword Coast, went mad as a result, and crawled, Gollum-like, into the Great Rift.

Cursed Sword of Berserking -- Smaeluv Orcslicer in the Den of 7 Vales (Also in BG1)
Ring of Folly -- Svirfneblin Settlement (Also in BG1)
Backbiter Spear -- Riti in the Imprisonment Crystal (Dates from BG1, but not legally obtainable)
Bracers of Binding -- in a "window" in Ust Natha (Also in BG1)
Ring of Clumsiness -- Deirex's Tower (Also in BG1)
Trahcie's Plate -- sold by Ribald in Chapter 6

There are, of course, also a large number of Cursed scrolls and Potions, and the reward recieved from Pontifex for completing the Ritual quest is Cursed as well.