BT is teaming up with Wi-Fi sharing service Fon, to give all its customers the option of joining the Fon shared Wi-Fi service.

As predicted back in February, BT is giving its broadband customers the option of joining Fon, and using Fon community's shared Wi-Fi. BT's Home Hub gateway will include the Fon software as an option, and customers who take it up will share a portion of their bandwidth with other users, in exchange for using the Fon service for free at other Fon user' hotspots.

BT has more than three million customers, so this is a big endorsement of the Fon concept, which has suffered some criticism from ISPs who object to their bandwidth being shared. Outside of BT, there are around 190,000 Fon hotspots round the world, and 500,000 people signed up to use them.

“This is the start of something very exciting for BT," said Gavin Patterson, BT Group managing director, consumer. "Today we are launching a people’s network of Wi-Fi, which could one day cover every street in Britain." The service will be promoted with the slogan “Wi-Fi for everyone, I’m in.”

BT did not mention its converged cell phone, which uses Wi-Fi to give cheap calls over home Wi-Fi, but confirmed that Fusion users will get free phone calls at more places than before. This was not mentioned in the release, but BT confirmed that Fusion is still a live project, though its 40,000 users isn't a hugely impressive sum.

Although BT Fon users will have access to BT's OpenZone hotspots, the deal does not give Openzone access to the wider Fon community - though BT pointed out they are free to buy vouchers to access BT's public hotspots.

BT has invested in Fon and gets a seat on the Fon board, joining other investors including Google.