How to sync files and folders outside the dropbox folder

To sync a folder outsider the dropbox folder, we need to create a symbolic link of the target folder to the dropbox folder.

On windows:

Use either the JUNCTION utility from Sysinternals, or the MKLINK command built in to Windows Vista and Server 2008, for example:

junction "C:\Documents and Settings\User\My Documents\My Dropbox\DesiredFolder" "C:\Path\To\DesiredFolder"
mklink /D "C:\Users\Steve\Documents\Dropbox\DesiredFolder" "C:\Path\To\DesiredFolder"

Or, if you prefer a GUI, install Link Shell Extension.

[You could also] use SyncToy to echo changes from another folder to your Dropbox folder. This keeps 2 copies on disk though.

On Mac:

Use the ln command, for example:

ln -s /path/to/desired-folder ~/Dropbox/desired-folder

This works with files too:

ln -s /path/to/desired-file ~/Dropbox/desired-file

Another easy way to do this with Terminal is type the ln -s part, then from Finder drag the folder/file that you want into the Terminal window then drag the Dropbox folder and hit return.

Note that an Alias file or folder does not work.