Upvote:2
Another user of this site put me onto this:
Pay as You Go Sim with Data Wiki
It covers a lot of the pre-pay options for many countries around the world. It describes itself as:
This wiki collects information about prepaid mobile phone plans from all over the world. Not just any plans though, they must include decent data rates, perfect for iPhone, iPad and Android smart phone travellers, as well as mifi users.