GSM doorbell

Dutch wireless start-up Waleli has announced plans to roll out its 'GSM doorbell' internationally. The Waleli GSM doorbell is a clever application for GSM mobile phone technology, allowing people to answer their doorbell, talk to visitors, and even open the door, whether they are at home or not via their mobile phones.

At home, when the householder doesn't need the GSM mobile functionality, the GSM doorbell can be switched to normal doorbell mode with a single keypush.

Source: Cellular news