If I'm not mistaken, AT&T GoPhone unlimited internet is still available until the middle of November and can be activated for 3 months in advance via customer service. In other words, you should be able to get unlimited data in December by activating for two months in November (2x $19.99).
As for international long distance on AT&T GoPhone, it is $0.39/minute. Here's the full rate table:
http://www.wireless.att.com/learn/po...ance-rates.jsp
While in the US I use StanaCard for International toll bypass. Rather than being your typical calling card provider, they give you 10 US based DIDs you can map to the numbers you would like to call overseas.
VladS
Mobile Phones: Nokia E72-2 (3G/GSM/VoIP), Nokia E71-2 (3G/GSM/VoIP), Samsung BlackJack II (GSM/3G)
Mobile Data Cards: Novatel MC950D, Huawei E220, ZTE MF668
Postpaid SIMs: CA: Fido - US: AT&T - FR: SFR
Prepaid National SIMs: DE: Aldi, Fonic - AT: yesss! - RO: Orange, Vodafone - UK: O2 & T-Mobile - US: AT&T & T-Mobile
Prepaid International SIMs: eKit, Sim4Travel
Dead Prepaid SIMs: United Mobile +44, United Mobile +423, ICQSIM and 09