We just finished a 15 minute voice chat from our hotel here in Halifax to my parents’ condo in Florida. They were using my Mom’s iBook and were dialed into an Earthlink account with the iBook’s internal modem; on our end was my MacBook connected by Ethernet. Using iChat voice quality was better-than-telephone, which seems like some amazing feat of technology.
They report, by the way, that Earthlink, which they signed up for when wifi was not in evidence, was easy to sign up for and works well. They especially mentioned the friendliness and efficiency of the Earthlink support staff.