Yeah, I graduated this summer - BS in mechanical engineering. I lived in Mason Hall from 2005-2009 though, and could see the psych building/former physics building right out my window(s).
I'm pretty sure I never went inside even once though... lol.
It's too bad that you'll be gone - it seems that people are split (at least us) about early vs. late January. Hopefully that doesn't prevent something from happening.
Actually, I don't leave until the 9th - so there is a window there. Perhaps Friday the 8th?
I'd say that the dorms are great for this sort of thing, what with all the extra rooms and everything - but they'll be closed anyway.
Maybe something could be organized with the MSU Audio Enthusiasts and Engineers? (Their website is here.) They would have the ability to reserve a room, in the Engineering Building or somewhere else - and they're definitely the sort to like this kind of thing. They'll love to talk tech too; almost all of them are EEs - and the faculty adviser, Dr. Wierzba, is great.
I never spent any time with the club other than talking to them on design day at the Union, but they seem a lot more easy-going than some of the other engineering clubs (e.g. the Formula team and the Baja team) that have more of a singular purpose and all-important competitions.