Often I make Screenshots with my make I would like to share with friends. This is a big hassle. You need to upload every time you want this and then share the correct url with the rest of the world. Why not automate this on OS X?
Start Automator. Pick 'Folder Action' for the type of document.
OS X offers 'Folder Action', you can create a folder and then right click this folder and choose 'Folder Action Setup'.
Add from the library the action 'Run Shell Script', pick from the Shell /usr/bin/python and paste this script in the text area below.
You have to configure the first lines with your SFTP server name, username and remote dirs et cetera.
This script needs you to create an ssh key to do the upload without password.
See this page for more info.