Obihai Technology, Inc. via Amazon offers the OBi100 VoIP Telephone Adapter and Voice Service Bridge
(pictured) for $39.99
. With free shipping
, that's tied with our mention from early September as the lowest total price we've seen. (It's out of stock at other merchants, but $16 less than the best backorder price.) This adapter supports Google Voice, SIP & OBiTALK VoIP services.
Also available is the OBi110 Voice Service Bridge and VoIP Telephone Adapter for $49.99 with free shipping. That's tied with our mention from last month and the lowest total price we could find by $7. It supports SIP for services like Callcentric, Sipgate, Vitelity, Voip.ms, and more.