Windows/Mac/Linux: NoteSync is a lightweight application that allows you to manage notes easily, and offers two-way sync with Google Docs to keep your notes updated and always accessible.
Upon launching the program, it will ask for your Google Docs account information. Navigate between notes using the keyboard shortcuts (CTRL+J or CTRL+K), or create a new note by entering a title in the search bar and hitting Enter. You then can fill out the details.
Because it's linked to your Google Docs account, your notes are automatically uploaded to NoteSync. It's also a quick way for entering a new word document into Google Docs without opening your browser. I also found that by going into Google Docs and by putting other Google documents into the NoteSync folder, I could sync them to the desktop application (this works for Word documents only). The beta version of NoteSync is an Adobe Air application, available for free for Windows, Mac OS X and Linux. Though the beta version worked fine for us, the developers are also selling a non-beta release for $US4.99.