Being hands free and well be freeing. I've been experimenting with an older version of dragon naturally speaking for the last couple of years. I started using it for just commanding my pc but quickly started messing around with it for my AI robotics projects, syncing it up with various devices attached to my house like our lighting, heating, water, window systems and my cell phone. I have found great time savings in using these technologies.
Advantages of using a voice control system for your house
When i walk into my house i don't have to turn on 3-5 light switch's. When i leave my house my kids are running around over 3 floors and its time consuming to have to go back checking every light to make sure they are all off. Its easier just to speak into your cell phone "shut it all down" and your good to go. When you are doing something in a room for a long period of time you can save electricity by telling your system to shut everything else off. Many appliances get left on especially if you area busy person or have kids running all over your house like I do. You can hook up your water sprinkler systems to this also but it really isn't necessary if you get a cheap 5$ timer from your local hardware store.
What i found is a way to hook all this up with some free software online. You will of course need to get the right devices to control each. Afterwards you will have to sync them up with your controller of choice(desktop computer, cell phone, tablet etc) and do some adjustments with voice control software. But it is very doable even for the non-techie.It you really want to go all out you could hook up mics in each room or wear a bluetooth or headset around the house
Software
Epeaking software is the free one I was talking about. Its biggest benefit is that's its free. The downside is that you will have to do a little more tinkering with it.
http://www.e-speaking.com/free_pc_voice_control.htm
The best software that's the easiest to use that I started with was Dragon NaturallySpeaking Home 12.0, English. It runs about 50$
mics/controller
There are lots of reasonably priced mics for under 100$ that will suit your needs.Make sure they are omni-directional which means they will pick up sound from the entire area around the mic and not just directly in front of it.