Already on the market in the Netherlands, 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. All via their GSM mobile phones.
Bonus points to Waleli for recognizing that mobile's killer apps are connectivity and control, rather than content.
But do we really want to be this connected?
For an interesting look at some of the other ways Waleli is finding novel ways of using the mobile phone to control things around the house (your landline, your appliances) check out the Products tab on their corporate site.