This is so funny. I did something similar to this and it took me and my brother in law about 4 hours to get all the collectibles achievements. I was gonna post a thread but looks like you already figured this out. Way better method then the other one.
We both had modded shields and pistols so it was pretty easy that way. One person blasts the opening and kills all the clap traps and the other collects the loot. Make sure one of you has a solider with an ammo regeneration mod.
Funny the rarest item for me was pizza's.
Last edited by Spanish Assault; 02-13-2011 at 05:10 PM.