Klipsch has provided an upgrade for their G-17 Airplay speaker that will allow single users to stream audio wirelessly to the unit without a router based Wi-Fi being available, using the new Wi-Fi Direct support.
Wi-Fi Direct basically allows you to connect a single device to the speaker for wireless streaming without having both units connected to the same wireless network, which is required for traditional Airplay streaming. The upgrade is available through the dedicated free set-up app that you can find in the App Store. Android users can also stream wireless to the Klipsch G-17 using the dedicated Android Music Player app.
Wi-Fi Direct is slightly different than the AirPlay Direct feature found in amongst other the new Libratone ZIPP.