I strongly encourage those who do not use technology to consider using one of these.
Thermostat - Ecobee. It is not just a themostat, it can also tell when someone is at the house. It has a sensor that sense movement in the house and set the desire temperature or according to schedule. When guest is away, sensor will follow the away schedule and vice versa. You can even control that temperature wirelessly from your phone in case you experience some difficult guest that decided to have a summer sweat party in the winter time.
Entry door - Samsung smart door lock - I am not a big fan of using wireless door entry. I am just concern about hacking. Thus, this is perfect for me as i do not want the door entry to be control wirelessly. It has a finger print reader, keypad and RFID card reader for extra security. Most time, a keypad code will be sufficient for my guest. Random access code will be provided to my guest and there is an added feature where they have to enter a random number first before access code. Thus throwing off those who try to figure out the combination from the finger print traces.
Garage door - Chamberlain garage door opener with MyQ. This is also another must have if you want to know if guest didn't close the garage door as it will send alerts to your phone wirelessly. It also will give you info when was the door last open or close for how long.