This is being done through php which zips the files into a package and then sends them for download to the client.
I have now implemented a similar facility on the Photo Dharma website, so that all the photos on a given page can be downloaded in a zip.
As they are published in different sizes the zips offered are either Slide size (roughly 800px by 600px) or original size (up to 4320px by 3240px).
The links appear and stay in sight on any page of the site where photographs are available and should make download and re-use much easier.
As some of the pages offer a large quantity of photographs it should be noted that some of the zipfiles are over 1GB in size, but most are probably around 300MB – 500MB.
I hope this will lead to more people making use of the materials and will enable people to make more Buddhist works from them.