This paper presents ongoing work toward the development of one-handed interaction techniques for mobile devices with a small touch-screen. This work comprises three main parts: the analysis of the state of the art, the development and the evaluation of novel interaction techniques, a proposal of tools that would help designing new techniques. This paper presents the work that has been already performed on the first two phases and some ideas for developing the last phase. Keywords Mobile devices, visualization, interaction technique, one-handed interaction, thumb gestures. ACM Classification Keywords H5.2. User Interfaces: Input Devices and Strategies, Interaction Styles, Screen Design; D.2.2 User Interfaces.