ThinkGeek has an entire catagory for “Cubicle Warfare,” including Siege Weapons.
A friend of mine has a father who is into this, albeit on a smaller scale than AEG (about a third that size, IIRC.) I’ll have to find the video.
That’s some good thread drift
Some tech specs if anyone’s interested
Our constraints were an 8 ft uniform thickness throwing arm and an 80 lb counterweight.
Our first blueprints:
We moved the location of the trigger to higher up on the base, and the supports aren’t in the exact same spot, but pretty much everything else is the same.
The trigger mechanism:
The axle and bearings attached to the throwing arm:
Baby’s Baby
This is a torsion-powered onager built out of popsicle sticks, string, and construction paper.
Oh, how the mighty have fallen…
Just kidding. Looks neat!
I forgot to mention why I built it.
Next week, Society of Women Engineers is going to the Boys and Girls Club to teach kids how to build siege weaponry . . . I mean science, it’s about the science. And stuff. And junk.
Good gods. Now picturing Fast Times at Ridgemont High…with siege weapons. :eek:
I attend the annual Punkin Chunkin near my home which has, among many other great machines, the completely awesome Yankee Siege:
My brother-in-law has an air cannon in the competition, but there’s just something so cool about the trebuchets and catapults. Also, nice work on your trebuchet. 
We do what we must because we can.