Day One is a fantastic, refreshingly polished journaling app from Paul Mayne for iPhone, iPad, and Mac. I love it for general journaling (aka, a diary), but its flexible nature lends itself to any number of uses from a travel log, a work journal, baby books, a workout or diet log, and much more.
If you’re in the “I really want to try Day One but I have no idea what I’d use it for” camp, Paul rounded up a ton of blog posts people have written about all the unique uses they found.
I use Day One as my primary way of keeping track of notes/quotes/links for stories to write in the future — sort of a way of archiving thoughts. I love the quick access provided by the toolbar portion of the native Mac app paired with the iOS apps.
I like the movie log idea as well.