The Live Chat might be affected by the recent update to Java (version 7 update 51) if the chat uses Java (as many things on the Internet do). If that's the case, go into Control Panel, double-click Java, go to the Security tab, click the "Edit Site List" button, click Add, type the URL that the Live Chat uses (including the http or https part) in the box, click Add again, ignore any warnings, and OK out of it. Then try the chat again.
We use an OBi100 with Google Voice (free) as a backup phone.
http://www.amazon.com/OBi100-Telephone-Adapter-Service-Bridge/dp/B004LO098O