Here's something I've been thinking about. If you have a VoIP phone system in your house with your own phone switch (like Asterisk) why couldn't you hook in a transceiver to monitor your local repeater or simplex frequency so you could monitor throughout the house without having to carry an HT? If you don't like the idea of having every phone in your house be an output for your local repeater (or maybe just a few phones) you could easily setup a DTMF tone selection that would ring a certain phone, or all your phones, when someone dialed the special number on the radio side.
Lots of ideas that I'm thinking of in regards to this but I just haven't thought about putting them all down. I'll continue this thought at some point in the future.