Mass Effect 2's newest available firearm spits electrical bolts and looks like someone weaponised a jumper cable from a fetish dungeon. If I knew what one of those looked like. A fetish dungeon, I mean.
Meet the Arc Projector, available to Cerberus Network subscribers - which means anyone who bought a new copy of the game and got the access card, or ponied up the $US15 to get the DLC. From the description on the Mass Effect official site, we can expect some high area-of-effect:
The Arc Projector ionizes targets with a non-visible laser to ready them for a high-voltage electrical attack. As the lightning-like bolt hits its first target, a sophisticated auto-targeting system paints succeeding targets with the ionization laser, allowing the electricity to take the path of least resistance and arc between them. An entire enemy strike team can be shocked to death with a few pulls of the trigger. Careful aiming will also allow the user to arc shots to nearby explosives as well.
You'll need heavy weapons training to handle this sucker. It also has a charge time of seconds, which is faster than the other heavy weapons currently on Cerberus, but not exactly lightning fast.
Mass Effect Arsenal [Official Site]