I know this is an old post, But I feel I'd like to comment. I like the over all idea, but I feel the price per unit is going to be an issue. Not to mention that if I read the faq right, you can't call numbers on the regular phone system, you are restricted to other Sipphones... which kind of makes the phone units kinda of useless unless you know alot of people with the units. The plug in unit would be ok if there was a line switcher so you can go between regular phone line and sip. A good idea all in all, but practical... its still to early to say.