I just released the first official version of DroPub. It's a mute little OS X application which makes drop boxes and sending stuff to remote servers as simple as it gets — just put a file in a regular folder and you're done.
Try it out — simply download, double click and create a folder.
Uses SCP (secure copy over SSH) and thus you need to add your SSH key to the remote server in order for things to work. A future version will introduce storing of passwords in the KeyChain.
It normally lives in the menu bar, but can live in the dock also.
Virtually unlimited number of folders can be watched and configured.
Further reading: How I wrote DroPub in two days.