It's Not What You Have, But How You Use It: Compromises in Mobile Device   Use
  As users begin to use many more devices for personal information management (PIM) than just the traditional desktop computer, it is essential for HCI researchers to understand how these devices are being used in the wild and their roles in users' information environments. We conducted a study of 220 knowledge workers about their devices, the activities they performed on each, and the groups of devices used together. Our findings indicate that several devices are often used in groups; integrated multi-function portable devices have begun to replace single-function devices for communication (e.g. email and IM). Users use certain features opportunistically because they happen to be carrying a multi-function device with them. The use of multiple devices and multi-function devices is fraught with compromises as users must choose and make trade-offs among various factors. 
Manas Tungare, Manuel Perez-Quinones