Well Its so dry here I built a DIY humidifier the one with the bottle and the air stone you see all over the internet, but it sucked so bad It was intended for a much smaller environment.
So I built a real Humidifier intended for a much larger space.
Here is what you will need to build your own Evaporative self regulating Humidifier on the cheap.

Step 1: What You Will Need

First a pet water dish with automatic refill.
A few super thick sponges
A small fan with switch (very quiet one from radio shack)
A tupperware plastic square bowl that is about the same size as the open part of the water dish
4 screws or bolts/nuts

Step 2: Cutting Holes

First cut four holes in the sides of the Tupperware don't cut all the way through the dish you want holes not spaces(pic 2) then measure the fan hole on the bowl it will be mounted upside down so with a sharpie marker you should be able to figure out where to cut plus if you got a dish that is clear plastic its easier
Next screw or bolt the fan to the bottom of the bowl (see pic 1).

Step 3: Install the Fan

Make sure the air blows down when the bowl is seated upside down.
Now cut the sponge so that one piece fits in each of the four sides of the bowl (see pic 2) and covers only half of the openings on the plastic bowl so that the air can escape(see pic 3), and place it all in the auto pet water dish (see pic 1).

Step 4: Fin

IF it looks like this then all you need is some water and then turn on the power.

I got this Idea from the HowStuffWorks.com its a perfect example of a evaporative humidifier.
If the link works you can view it here--> http://home.howstuffworks.com/humidifier3.htm

Enjoy the wet air