Excellent homesteading website.
How to Use a Small Farm for Tax Write Offs | eHow.com
Here's one person's take on what a 100' x 50' home lot can provide as a small farm. Depending upon your local city codes you may not be able to have things like the pigs (maybe goats, if any meat / dairy animal at all), but think of all the food you can grow yourself. And if your city allowed hens...
2-liter bottle of water in roof provides as much light as 50-watt light bulb. Saw a tv program about this and how people were introducing it to natives in poor countries who dont have electricity and can't afford solar since they live in shacks with thin roofs this was a perfect solution Ingenious! I will be trying this if i ever have a garden shed and/or chicken coop.