http://www.2n.cz/en/products/intercom-s ... tView=menu
http://nesscorporation.com/ness-interco ... -131b.html
http://www.mobotix.com/eng_AU/content/view/full/225139
http://www.amroad.com.tw/
http://www.advanceip.com.au/shop/index.php
To make it ring any or all phones in a house, I've got a cheap computer running what is effectively a telephone exchange doing the call routing (I'm tech savvy enough to set this up myself, otherwise it would be an additional cost to get someone to do this for you). Without this, I think you can only do a peer-to-peer connection, i.e. ring a single phone.
The models above do SIP/VoIP, which is a standard. There are cheaper alternatives, but I suspect they use proprietry protocols.
I forgot to add, the intercoms I linked above do both audio and video- which lets you take a photo every time the door bell is pressed, or let you stream the video to your mobile phone. There are SIP (voice) only door stations which can still be set up to ring any phone- obviously these voice only door stations are cheaper