PTel/PlatinumTel APN Settings
Name: PTEL MOBILE
APN type: defaul,supl,mms,admin (also works to leave this blank)
From customer service, and tested to work as of 04/03/13. Again 06/06/13, with blank APN type.
These settings I also tried, and they also work: http://forum.xda-developers.com/showthread.php?t=2075991 (edit: probably not working before, same as PTEL site below)
These settings on the ptel.com website do NOT work: https://www.platinumtel.com/support/phonesettings