Leopard’s Time Machine has an option to exclude certain folders from being backed-up. iTunes movie rentals which usually weigh in with greater than 1 GB are a prime example for what should not be backed-up. Unfortunately, movie rentals are stored in iTunes’ Movie folder–along with all your other movies that you may have purchased, or made yourself. So what to do?
Smart folders come to the the rescue. The trick is to identify what to put into the smart folder. Create a new search and save it to the sidebar. The picture below defines the settings:
Then in the Time Machine preferences, simple select and exclude this saved search: