Poor Kali is a bit misunderstood, as, perhaps, any goddess with her particular skill set might be. She is the goddess of death and destruction, but more metaphorically than literally. What she kills isn't man (or woman), but the ego. And as for destruction, she symbolizes the natural passings (physical, philosophical, emotional) that come with change and time.
Personal attributes: loyal and compassionate to followers, but you don't want to mess with her. She doesn't politely swallow her rage. She acts on it. And how.
Channel this goddess: When passive aggression just doesn't cut it anymore and you need to speak your honest-to-goodness mind; when faced with the inevitability of loss; when confronted with worthless computer technicians who really have no idea at all why your DSL line won't work and keep passing the buck.