New in iPhone OS 3.x, you can sync notes from the Notes app on your iPhone back to your Mac. To turn this on, select “Sync notes” from the Notes section of the Info tab for your iPhone in iTunes.
One minor problem. You may unexpectedly find duplicate copies of your Notes in other locations: In the Inbox listings for each of your mail accounts (such as Gmail or Comcast). You probably have no interest in maintaining these duplicates. So how do you get rid of them? It’s easy:
Go to Mail’s Preferences window. From the left column of the Accounts section, select the first account that is showing duplicates. Next select Mailbox Behaviors from the row of buttons. At the top of the window, you should now see an item that states: “Notes: Show notes in Inbox.” Make sure that this option is disabled/unchecked. Repeat this for each mail account that displays duplicates. Done.