It seems I can use Gophone SIM card to use Data connect pass plans.
https://buyasession.att.com/sbd/Common/ShopRatePlans.action
But, which price plan should I choose when I use my WIFI router like a Sierra Wireless 754S AT&T Mobile Hotspot？
Then what is the diffrence between Mobile hop spot plans and Data connect pass plans?
Only roaming?
Please let me know.