here's no reason your privacy should stop at your back door---your back yard is another part of your home. The options for privacy landscaping are many, and there is sure to be one that reflects your tastes, needs, limitations and budget. Before considering any of these, however, be sure to check with your neighborhood homeowners' association and local zoning/building boards to ensure your plans are up to code. Failure to do so can be very costly.
Fences can afford a homeowner surefire privacy, but some styles can also be unwelcoming. They blow over in high winds, block out light, can be troublesome to maintain. Some may even be cost prohibitive. Just because you would like some privacy doesn't mean you have to block out everything happening outside your property lines. Chain-link fences address that problem somewhat, and picket fences have a certain charm, but there are more options.
This is a specialized idea for those who want to give their place an old, colonial look: Classic New Englanders love their rocks, and low-slung stone walls are a signature of the local architecture and landscape. The look has become common in many parts of the country, with homeowners using stone walls to set off their front and side yards.
Sometimes the best privacy protectors are the ones you plant. Hedges can provide as much or as little privacy as you need without the imposing attitude of a fence.
You can even create your own hills, or berms, to set off your back yard, then cover them with plants. You may wish to check with your neighbors (or even team up with them on the project) as this could cause drainage problems.
Small trees, like hedges, can also provide privacy while allowing the sun to shine through and the wind to breeze past. They do require frequent maintenance, such as watering and pruning. You may also need to protect them from small mammals by using a small barrier called a tree guard.