Valhalla is the only map in the beta where you can fly high with the Mancannon. There are two at the top of each of the bases on opposite ends of the map. You can easily recognize them by the bluish streams of air emitting from their vents. Jump in them, and they'll launch you towards the middle of the map.
When carrying the flag or the bomb, the Mancannon is useful for quick escapes and covering ground quickly. On the flipside, keep your ears open for the distinct sound the Mancannon makes whenever it launches a person into orbit. That way, you can draw a bead on them as they descend. They'll be dead by the time they hit the ground.
But what's really cool about the Mancannon is that it'll launch anything. Try driving the Mongoose up your base's ramp into one of the Mancannons for some spectacular crashes. You can even kick the boxes nearby into Mancannons sending them flying. The boxes will blow up whenthey hit the ground, but it's hard to catch someone with it. If you see an enemy hop in the Mancannon and you're quick enough, try tossing a grenade after them. If you're lucky, it'll detonate in mid-air, blowing them up like fireworks.
