Yes - I've heard of them too - but I would recommend that you make the investment and get passports. With a passport you don't have to worry.
Expand your horizons!
I can only speak for Canada - but you can't get on a plane in the USA to Canada without having a your passport open and available - they are EXTREMELY sticky about this. (Conversely, travelling into the USA from Canada, they don't seem to check....governments - go figure...)