My sister and I and a friend are renting a house near our college while I take a summer class and they have summer jobs. We're in the Midwest and the other day we had to sit in the basement for a tornado warning. The basement is super dusty and my sister has allergies, and also I like disaster preparedness and making my own life difficult, so I appointed myself to be the basement into a decent tornado shelter. My sister extracted a promise that I wouldn't become a crazy stockpiler, and I started cleaning. Here are the "before" pictures, and I'll update as the place turns into somewhere we can comfortably sit out tornado warnings and sleep if necessary.
Oh. My. Gosh. This basement hasn't been cleaned in years. I, on the other hand, am going to get cleaned ASAP.

Hi guys.
So here's the basement before any serious rearranging and decorating, but after a lot of cobweb-removal. You start down the stairs:

Okay, it's kind of grubby and the stairs themselves aren't in great shape, but it's an inexpensive rental for college students. No big deal.
You keep going.

There's something HVAC-y leading out through what used to be some sort of door. And yes, that's a coat hook holding the ex-door shut.

That's...different.
You turn the corner and come out into the basement proper:

Okay, slightly sketchy college-student basement. Whatever.
There's some basic basement stuff: random things previous tenants left, the furnace, a no-longer-functional laundry sink. There's also water pipes coming out of the ceiling and draining into...

...a trash can with a pump in it. Why, what do you have in
your basement?
Also we have a tank that holds or used to hold some sort of gas.

Peace, y'all.
You know that scene in all those movies where they take the hero down into an incredible janky basement and plunk him in a chair and interrogate and/or torture him?

Yeah, they filmed it in my house.
Today I mostly swept dust and cobwebs out of the rafters. There are diagonal supports going between the rafters that collect so much dust the first time I swept a clump down I thought it was a dead mouse. I'm betting that by the time I'm done sweeping I'll have a pound or two of dirt to throw away. And speaking of cobwebs, look what I found in one of them:

Does anyone have any idea what it was when it was alive?
Next I'm going to sweep off the walls and the air pipes, then wash the windows. I'm also going to do something about the wiring. The ceiling is full of about thirteen different systems of electrical wiring, most of which seem to date from a century before the house was built. Here's a taste:

But that really doesn't do it justice. Imagine if you were staying at someone's house and borrowed their computer, and then went to them and said, "Why have you installed Internet Explorer
and Firefox
and Chrome
and Opera
and Safari
and Seamonkey? Also, you have a Linux virtual machine on which you're using Wine to run IE
again. WTH?" and they just said, "Don't ask, man." Yeah, that's what the wiring in my basement is like.
Once it's decently clean, I'm going to fix up some shelves and store some food and water, flashlights, first aid kit, that sort of thing. I'm also planning on retro Civil Defense signs to label the shelves. Wish me luck!