YSK that "phased" means to change states of matter, and "fazed" means to be disturbed by something.

The phrase "x happened, and he wasn't even fazed" seems to becoming more and more common, however I very often see people use the wrong homophone.

edit: I should have kept my verb tenses consistent, sorry.

"Phased" means that something has changed states of matter. "Fazed" means that someone or something was disturbed by an action.