[Holtzman]

Ideally, equilateral triangles water jetted, or cnc'd or whatever into the 2x2 would be great. Assuming you don't have these resources, I would suggest 1 inch holes every 2 inches with 1/2 inch holes every 2 inches in between the 1 inch holes, 1/2 an inch from the outside. Its difficult to picture from my description, so I've attached a model. Also, make sure you offset the sides by an inch so you make sure you have the most material possible at the edges while still removing the same amount of material.

If you going to drill one set of holes down the middle, MAKE SURE YOU OFFSET THEM. I've seen many teams that don't do this, and their just throwing strength away. See attached jpegs for more info. The pictures can explain it better than I can. Offsetting the holes doens't change the weight, but you conserve strength considerably when they are offset.

Sorry for any vagueness. PM me for more info