I want to throw in my two cents for Z-Wave as well
I haven't gone all out like Vanguard but it is pretty great and helpful as well to have it around the house.
I'm using a Vera 2 (Vera 3 is available now or a Vera lite if you don't need all the functions of Vera 3) and it's a pretty interesting system.
Cause it hasn't been explain here I will give a quick rundown of the system.
Z-Wave is a mesh network so the more devices you have the better the communications it will use other Z-Wave devices as hops to the device you need so no need to worry about distance of your Z-Wave device.
The Vera has a lot of great functions in general setting up scenes which are just a container for your program they are simple and easy to create you don't need to know code to get it to turn stuff off and on or set a lighting percentage with dimmers etc.
It does allow you to add extra coding and improve the functionality to other non Z-Wave devices which is great so if you have wifi enabled stuff you can have them triggered with your Z-Wave stuff.
The Vera is just a router for Z-Wave you can either have it as your main router or have it connect to your route it's handy as a backup if a router dies on you but it's pretty flexible as well.
Now for my setup I use everything android and use HomeBuddy on android for most things.
I did grab a few $50 4.3" Android tablets for my upstairs and downstairs and use some intercom apps on it as well to talk upstairs which is handy.
Here is a pic

That's when I was testing it out.
Also cause i'm using android it's handy for access cams too

I also have a plugin to stop and continue music and movies on my XBMC in the lounge so when I get up to open the door I can pause it as well.
I had a list of stuff i had written out that can be used and i use when i started with the HA stuff here it is below.
• XBMC will turn off all the lights when playing a movie and turn on the lights when finished but also turn on a lamp when paused so you can see your way to the kitchen.
• Tablet on the side table in bed just tap the PS3 icon and it turns the ps3 on and changes the HDMI input to ps3 and pressed again it checked to see if ps3 is powered on and powers it off and puts input back to XBMC.
• Play select playlist on XBMC as wakeup music and slowly turn the light from 10% to 100% in the course of 10mins to wake up easier (Like a sunrise)
• Press Coming home button on phone and it Reads the temp inside the house and turn AC on if needed so house is cool when you arrive home.
• Motion Sensor outside front door and notify the Phone when motion detected and turn on IP Cam to view.
• Motion Sensor outside front door to turn light on at night based on time unless sleep mode is activated.
• Sleep mode on tablet that turns off all lights downstairs and sets a variable to 0 so other actions don't run unless variable is 1
There is a lot of other things that can be done too like sending IR signals to turn stuff on that you can't fully automate with just Z-Wave and other things too.
Lots of people have added in stuff to their wifi enabled stuff one great thing that I will be doing soon is Virtual blinds (Just smart film) it's wifi enabled film that lets you make a window see through or solid and that can be added onto vera no problem.
Plus on the somewhat crazy side I will be making an interactive mirror
I'm just using a monitor behind 2way mirror tint in the bathroom which will display weather and news and allow music to be turned on for the shower using a haptix from kickstarter for the touchscreen (It's like a kinetic) so that will be a fun project to play around with it will also be handy to play movies on while in the bath too so that will be a very fun project
