Providing the initiator of a conversation with awareness information about their target's availability can improve interruption timing. Providing this information, however, can be particularly challenging with mobile devices, which are carried by users in a range contexts and have limited audible and visual display possibilities due to possible background noise and small screen size. Haptic or tactile displays present a potentially useful alternative, as interaction with mobile devices is often by touch. This paper reports on a dual-task comparison of awareness information usage on a mobile variable-friction tactile display vs. a visual display under conditions that varied in task type and task workload. Participants using the tactile display performed marginally better on the primary task, but were less accurate and slower on the awareness task. However, there is evidence that some of the awareness task differences dissipated over time. Self-report data also suggests that people's experience with the tactile display was generally positive and improved over time.