Re: Device to Bridge Insteon over IP?
Bridging INSTEON over IP is probably not a particularly great idea given how linking works. But there are other non-INSTEON solutions.
Something like the WebRelay
would probably work - not sure exactly how/if it can connect outwards, but it appears to have some XML interface that Indigo could poll periodically to check the status of the relay.
If the Twine
were ready it might work for you but they aren't shipping until June and it'll take a little while to figure out how to get it integrated with Indigo.