The proliferation of wireless technologies, mobile computing and Internet have spurred the development of innovative location-oriented services. For accomplishing this, an accurate and time-efficient location determination system is required. For indoor positioning, WiFi-based solutions are prominent due to the widespread availability of WLANs (wireless LANs). More recently, the RFID (Radio Frequency Identification) technology has also been suggested for its own key prospects. However, both of them suffer from their own limitations. In this paper, we propose the integration of both technologies for carrying out simultaneous tracking of users with multi-modal devices but with diverse capabilities. Taking advantage of this multi-modality but also diversity is investigated for enhancing the system accuracy. Results based on extensive simulations validate the superiority of our proposed hybrid scheme over its stand-alone counterparts