I was watching The Screen Savers on Tech TV this morning(12/10/03) and they had a caller who was wondering how to do a wireless camera on his 300 acres to keep tabs on the snowmobiles and such that like to use his trails. Interesting delema, as he has mostly undeveloped land with trees and scrub.
But I found a few solutions.
There are many people who have already made things like this themselves. Samuel Brown from the Viejas Indian Reservation in San Diego County, who has a good Native American language website, kumeyaay.org , has a page about his own wireless camera powered with solar panels.
There are also premade solutions and I would suggest starting with Alternative Energy Resources' website. They have not just cameras and such, but whole house solar solutions.
This brings up the subject of the power grid and both the reliability of the current power infrastructure as well as the possibility of self reliance for your own power. In some parts of the United States and Canada, if you have a power generator,solar or other, you can sell back any extra power into the power grid. This lets you get a little back from the power company as well as being able to help supply power to your neighbors.