People who sign up for BT's new TV-on-demand service will get a combined freeview box, VoIP phone and 160GB personal video recorder for just £100 - without committing themselves to a penny more.

BT's 2.3 million broadband subscribers will be able to use the box to view, time shift and record any of 32 digital Freeview channels.

Other content can be bought on a pay-per-view basis; BT says it is the only service of is kind not to demand an up-front subscription, though there will be subscription options.

Users will also be able to make webcalls via a window on their TV, though BT could not say at this stage whether they would need to buy a mic.

There will also be a catch-up service, allowing you to view programmes screened over the past week; as with similar services this is currently restricted to BBC channels.

People with capped broadband connections will have to pay BT for any extra bandwidth used to deliver Freeview - and it is an open question how long affordable uncapped broadband can survive this phase of online development.

It is also unclear whether you will buy your bandwidth when you pay for a movie, or whether there will be a separate charge. 'Some details have to be worked out,' a BT spokesman said.

The new service, BT Vision, will be launched in autumn and broadband subscribers can sign up now. At a later stage it may be available via service-providers who resell BT access.