Along with the rapid development of information and communication technology, more and more mobile commerce applications are available. However, what is the user's perception and reaction of those new applications? It is critical to study the factors that influence the user adoption of mobile applications. In this research work, we propose an extended technology acceptance model, which is called mobile services acceptance model, with a consideration of trust, context, and personal initiatives and characteristics factors in addition to perceived usefulness and perceived ease of use. Furthermore, in order to demonstrate the applicability of the mobile services acceptance model, one case study with respect to the user adoption of the mobile application---FindMyFriends is presented.