http://www.solwise.co.uk/webcams.htm
I don't have any association with the company.
What I was searching their site for was ethernet bridge devices using the household mains - to reduce cables and to be more reliable than wireless. Are there any electrical (power) engineers on this board who might be able to give an indication of how far signals might be 'broadcast' from the house beyond the ring main?
EGKK - I don't know how you would get to transmit the signal without using the internet or a phone line. For a start you would a transmission licence (in the UK anyway) and a line of sight connection unless power etc. wasn't an issue.
Is this to monitor remote premises? I.e. is there power and a phone line there? If so then it might be worth considering an old PC and dial up / broadband connection to get the remote connection.