Water, Water in my Sink, but I don't have a Drop to Drink

One major difference between my native Minnesota and Idaho is the issue of water. Generally, back home, we can just plant some things and nature will run its course, with the occasional sprinkling. But in Idaho, we are in the middle of a desert-like area. Maybe it is considered an actual desert; as an out-of-stater, I am no expert on the subject.
Water is something that community gardeners will really have to worry about. Since we clearly can't rely on rainfall, we have to figure out some sort of irrigation. As of now this is still something I know very little about... but my research today, mainly water-focused, has given me a few ideas. Hopefully they are in the right direction.
First, I came across the terms "greywater" and "blackwater". Greywater, according to the UMass Extension, is defined as "all the non-toilet wastewater produced in the average household including the water from bathtubs, showers, sinks, washing machines, and dishwashers". Blackwater is essentially the rest of it; water from toilets, with waste in it, etc. The good news and potentially useful tip for us here in Idaho is the possibility of recycling greywater and using it to water plants. There are some precautionary measures to be taken, however. At this website, they instruct you how to build a greywater purification system. Here as well.
I don't know about you, but that seems a little daunting to me. The U-Mass Extension website claims that you can put grey water directly onto your soil. There are special steps you need to follow, like this website suggests. Transportation of greywater could be an issue to some garden sites, and I realize this idea isn't perfect, but here's a scenario. Say there is a garden that is loaned land from a church (ideally located close to it). The church has a supper, and they save all their greywater (or most of it) in a bucket in their sink or trap it somehow. Then this water can be transported to the garden. I'm sure there are some flaws in this plan; for instance, Greywater Guerillas emphasizes the need to use the water in the time frame of 24 hours. Which could be a problem for some gardeners. And greywater should only be used if it has all-natural ingredients (i.e. if you don't use really nasty, chemical soap to wash your dishes). This could also limit its use. It's still something to keep in mind, however, especially in a place where water is scarce.
Another idea is to harvest rainwater. This might not be incredibly fruitful, since as I said it doesn't really... rain here! But I found this guide online from the Montana State University Extension about harvesting rainwater. It's only 4 pages long, as opposed to this one from the Texas Water Development Board, which is much more in depth. (By the way, before I forget, I got most of this stuff from here. This place has a LOT of water information.)
Another thought I had was about rain barrels. This may not be the most effective system in a rain-starved area, but the Maryland Environmental Design Program has this "recipe" to build a cheap (they say $15!) rain barrel.
There are ways to conserve water, most definitely, and hopefully when this program is established I can point people in the right direction. Water is a huge issue, obviously, when dealing with gardens.

In other news, I've been doing some research about growing stuff in a basement... I live in a basement, but I don't want to let that stop me during the winter. I'm not sure how well my plan will work, but it's worth a try. I've read some articles about "basement gardening" and they show pictures of long, flourescent tubes hanging from ceilings and loads of plants under them. I don't have that kind of room... so I think once I fix my table (whose leg cracked in a silly moving accident), I will take a lamp, put a natural light bulb in it, and see if I can grow a basil plant or something. I hope I'm not making a huge mistake... we'll see how that goes, anyway!

At some point, I will start putting pictures on here. It must be boring to have only text all the time!