Here's some more (I just got a chance to upload these pics, these are actually from back when i built Big Mike.)
Base Defense Turret
gun that can rip apart enemy squads or tanks. The four cannon on it have a damage rating when fired together that does... um... I think 8d6 damage. Ouch.
Turtle - AT Personnel Transport Sled
This is a cheap non powered transport for my army. Most of the cost is sucked up in the armor plates. This thing shielded can withstand a big load of damage. This is what the rope on the back of Big Mike is for.
Swallow - Small Hovercraft Attack Fighter
Just a small infantry support hovercraft. The three guns can do some damage to a group of minifigs. Best used as support for ground troops, like you see above.