One of the most common things people automate around the home are temperature controls. You can get thermostats that sense the interior temperature and raise the heat or turn on the air conditioning accordingly. Programmable thermostats can turn on the heat 15 minutes before your alarm goes off. Pretty simple stuff. From there it can get more involved. Some automated temperature controls can do things like lower the blinds when the sun gets too hot or close the windows once the sun sets. Others can detect humidity and switch on a humidifier. Some systems are being networked so you can ring up the unit on your cell phone and instruct it long distance.
To get an idea of what sort of automated humidity and temperature controls are on the market you can browse Temperature Controls & Sensors at Smart Home.