If you have a smartphone and your a BT Customer you can
access your BT calling plan from your smartphone and use your inclusive or cheaper 0800/0845/0870 calls .
You can use the BT SmartTalk app when you're at home, connected to your wireless BT Home Hub.
Out and about? Connect via wi-fi including 7.5m BT Wi-fi hotspots worldwide.
No wi-fi? The BT SmartTalk app will also work over your mobile 3G connection in the UK.
http://www.productsandservices.bt.com/consumerProducts/displayTopic.do?topicId=3...
Note app only works with I Phone and Android Smartphones.