Warehousing images in RapidWeaver

In order to achieve what is shown in the video, some conditions must be met:

You must be able to create a directory on you host
Your host must be able to run php
You must be willing/able to upload a php page to your host

The demo is done on RW 5 Version 5.1.1 (8238)

The only plugin used is the RWsymGaleryBox. I believe that any gallery plugin which allows specifying (and drag-dropping) urls of warehoused images could be used.
The php program I use is about 30 lines of code. I will publish it if there is enough interest - right now it lacks error handling and security hardening.
Unusable sample is here.
The resulting gallery in the video can be made prettier but this video is not about that.
Lastly, I am not a professional presenter so the video is raw and dilettantish. So if you have 2 more minutes, go and hit the video play.