When it comes to home security the only limit is how much you are willing to spend. Within that limit there are a number of systems that are affordable, and do all that they can to make your house safe.
The history of home security goes all the way back to when huts were just being raised from the mud. Back then the security systems were pretty basic; a dog, a son keeping watch, a prayer to the local gods. As society developed, those systems become more and more daunting; as the walls became taller and deeper, the dogs became more plentiful and armed guards were added to the defense, the son was replaced by sentries and traps, and threats of death joined the prayers. In more modern society, people were better able to pool their resources, so that the dogs became more ornament than useful, the guards evolved into police, and the walls disappeared as trade was seen as more important than defense.
Now society is looking back towards protecting the home. Security systems have become more personalized, and better able to deal with a number of different situations beyond mere security, such as emergency situations (like flooding and earthquakes, as well as medical problems). The security systems in place, however, are still based off the basic key and lock, even though that key may have changed from a piece of metal to a few number typed into a pad. The newest variation on this is biometrics.
Biometric systems are securities based on the person’s body itself, making the person himself a key to the system. Usually the system is limited to fingerprints only, but other body measurements may be involved as well, such body temperature, voice print, or even DNA analysis. The advantage to such systems is that they severely limit the persons that are able to access the house, as only those people with the matching characteristics can get past the security. However, there is the disadvantage that no one else can access the house, thus asking friends to pick things up is no longer an option. Also, there is the issue that any change in the characteristics (such as a fever or laryngitis) of the person will make it hard, if not impossible, for the person to bypass the security. Some systems allow for these changes, but those are top-of-the-line systems out of the reach of most consumers at this point. In general, biometric systems have a few flaws, but are generally good systems.
It is noteworthy that such systems are still in their infancy. As of right now, systems are rather inflexible, and require the person to have a back-up system. That back-up system ends up getting more use, especially by most visitors, but that’s because of how hard it is to add a person to the system. Otherwise, the systems show a lot of promise and should work into their promise, especially as systems improve and become more intuitive. When that happens, they won’t feel as invasive as some systems do now, and will become much more popular.