Never use a cruelty when a joke will do in its place

I'm sure that "tchau" and "ciao" are related, simply because both Portuguese and Italian are Romance languages (as in, they're probably both cribbed from Latin, not necessarily one from the other). It's really cool when you can start to see connections between two languages, if not in spelling, in sound. Other linguistic fun times: seeing structural similarity between two languages which are not in the same family.