Been using Gizmo to call from N800 in Japan to landlines and cell phones in the US for a month with the latest release (3.1 v76) No problems with outgoing audio, and the price is right (since the number is technically based in Nevada, all calls to folks in the US are ~1.9 cents/minute). Calls to Japan are the most expensive judging by sample rates (~3.3 cents/minute), but it still beats a phone card.

The internet here is rather ubiquitous, but I still wish I could get Bluetooth PAN working...