In response to a comment on my previous post, everything worked pretty much flawlessly for me. Refer-a-friend went through perfectly on two of the three phones, with the last one going through after only about 3 tries. The phone numbers were not displayed in the prepaid menu of any of the 2600s but that's OK since I could easily find out what the numbers were (yay caller ID!).
As far as the Wrong SIM error message goes, you MUST activate the phone in the area you said you bought the phone for when you bought the phone. Otherwise you may wind up with an incompatible SIM card (wrong region of Cingular or a T-Mobile SIM when you wanted Cingular, etc.) because Tracfone thought you were going to activate it in the area you said you would.
Also, if you want to activate a GSM phone in an area that Tracfone says there's no GSM service in, you MUST (yes, another must) use an activation zip that DOES have GSM in it.
Hope this helps clear things up...