Are mobile phones only useful when you're mobile?

I am a Computer Science Masters student at UBC working in the MAGIC lab and we are looking at whether or not mobile phones are useful in the home as well as when people are on the go.   Lots of people have thought that mobile phones would be a useful mechanism for controlling all of our 'smart' appliances in the home, but what about using your mobile phone as a secondary display for your TV as well as a controller?  

Let's say you and family just got back from a trip to the museum.  All of you have your photos and video from the day on your mobiles and as you enter the living room you are asked if you want to share your photos on the large TV.   You all decide to go through your photos on your phones and pick the best ones to keep in the family photo album.  You go through the photos on the phone and share the best ones with your family on the large display.   There are a couple of important ideas here.  One is you are bringing in content on your phone and you want to share it with others and second you are completing private tasks on your phone so you do not have to share everything all at once.

In the MAGIC lab, we did a user study looking at what sort of tasks users might want to do on their cell phones while in front of a large display and if using your cell phone is as efficient as using the large display.  We built a prototype that allowed users to 'grab' screen shots onto their cell phones, select some of these screen shots to share with the group and then build bring every one's screen shots together to build an outline.  Some of the tasks were completed only on the cell phone or the shared display or a mixture of both and all tasks used the cell phone as a controller to the TV.   We used the N80 Nokia cell phones so the resolution and color screens on the phone were quite useful.

While our initial results show that most users preferred working on the large display our next study is going to look at what would happen if the content on the phone has some 'private' aspect to it..will user's preference's change?   Also, we found that most user's were OK with switching attention between their phones and the TV screen and even though mobile phones today are not designed as a remote, users adapted well to this idea.  As phones become more powerful and continue to have more services available on them, we need to think about how we can and will use these devices in and out of the home.