Akimbo is a mod that will allow you to use two weapons at the same time, one for each arm! You can use two identical or different weapons. This enables new fighting techniques. You could simpy have double fire-power/fire-rate, or be ready for both short and long distance encounters with different weapons. You will use two separate "fire" keys for the two weapons. According to the "readme" file included with the mod, you can bind more commands to separately cycle the right and the left weapon, or to set a specific key for a specific weapon and hand.