Jeram's Bracers can be used to cast Wall of Death 3 times before triggering the cooldown.
Playing as a Barbarian, there is a set bonus to cast Earthquake at the end of casting Leap. That synergizes really well with an item such as Lut Socks.
This makes me wonder if there are other items, such as items that work for Witch Doctor abilities.
Are there any other items that cast abilities under certain situations, or otherwise augment ability casting?