Thank you for pointing me to this! To date I had not seen anything similar.

Perhaps the biggest differentiator is that PhoneCard works in the opposite direction, too. For example, you can purchase a phone number in the UK and have it forward to a US number. Also, PhoneCard calls you, while Ringo appears to make an outgoing call. In much of the world besides the US/Canada, incoming calls are free (even on a mobile/cell phone), so this means you pay for the call once instead of twice.