It is >>NOT<< completely free, and simple to ring up charges....
Read the FAQ section....here are some highlights
"membership dues are $3.80 and are only applied in months when you make calls. there are no minimum charges. for more rate info click here. "
"make a free call from your telephone by visiting our site and "zapping" the charge from your bill. "
"you can zap any long distance call less than $5 ($7 after january 1, 2001). for a domestic call that's a 140 minute conversation." (do they mean $7 per month, or per call???)
"you have 5 days to zap call charges. "