Share notes with other people on a mac
What you can do is go to your home folder, press "command + up" and open the Shared folder. This folder is fully accessible to all users. The files themselves though need to be made readable and writable to everyone. You can do this by right clicking on the file and opening "Get Info", scrolling to the bottom and changing permissions till they're how you'd like them. You can add users to the list for more fine-grained permission control, or just allow everyone to read and write it for simplicity.

EDIT: Sorry, I'm crazy tired. Some of the original post wasn't true...