BT Fusion launched a Wi-Fi fixed and mobile convergence service 
In the office, or at BT Openzone hotspots, for up to 60 minutes customers pay 5p for UK fixed line calls, less than the cost of a text; 15p for calls to BT mobiles, and 25p for calls to other UK mobiles. On the move all calls to both fixed and mobile numbers are capped at 25p for up to 60 minutes.
BT is initially offering two dual-mode Wi-Fi mobile handsets: the Nokia 6136 and the Motorola A910. Samsung’s P200 will be added to the range next month. Up to 6 Fusion Bluetooth handsets can be linked (paired) to BT Business Hub with up to 3 making calls simultaneously. Or up to 10 Fusion Wi-Fi handsets can be linked to the BT Business Hub with 5 making calls simultaneously The range for handsets connections between the Hub and handsets is up to 25 meters,
When combined with BT Business One Plan, BT’s triple-play package for mobile, fixed and broadband, prices start from £15 a month including the handset.
http://www.btplc.com