Haunted, Cursed, Possessed equipment. Ideas? Thoughts? What have you used in your campaign?

I had a play get his arm blown off by a bolter. Luckily for the player the cultist that shot him had a best quality cyber arm to use as a replacement. The players never stopped to ask "Hmm, should we put this cyber arm we got off a dead cultist, who was working for a Nurgal chirgeon on a player?" Sadly that player dropped out before I could mess with the character (see the movie Ideal Hands for what I was thinking of doing). Have any of you used cursed or problematic items in a campaign as a player or GM? I'm thinking of giving out items like they did in Deadlands, the item has benefits but also confers flaws (Wild Erps guns were great until you got surprised or shot in the back).

Any ideas on melee weapons or firearms? I want to give out a areotech sword that has problems to a player and I need ideas.