Omnipresent Wi-Fi access points (APs) periodically broadcast beacon frames to inform potential stations (STAs) about their existence. Beacon frames can be extended by adding additional information (so-called beacon stuffing) making it possible to deliver this information to mobile devices (smart-phones, tablets, etc. equipped with 802.11 interfaces) without the need for association with the local infrastructure. This feature can be used to support location-based information services (LBS) related for e.g. advertising local opportunities, temporary obstacles and traffic disturbances or emergency notifications. In this paper we discuss technical solutions that support LBS using 802.11 beacon stuffing. For a selected approach we present the design, implementation details and performance evaluation for Location-based Wi-Fi Services (LoWS) - a complete open source solution. LoWS supports an original, highly efficient way to encode information. The LoWS system can be integrated in an existent 802.11 infrastructure while the receiver application can be installed on commercial off-the-shelf Android devices. The LoWS system is modular with well-defined interfaces making it an attractive tool for modifications, changes and improvements.