Wouldn't you know it? Just when I was putting the finishing touches to my updated Photofeed Gadget for Google Sites, the rug was pulled from under my feet. In the best traditions of Murphy's Law, my valiant efforts to tame this unruly child in an unruly world coincided with the launch of New Sites as a long-term replacement for what is now known as Classic Sites. Since the new hosting service is incompatible with the old, no upgrade path is offered and both versions will operate side-by-side for the foreseeable future. In practice this means that users are now caught in a No-Man's Land where Classic Sites support is waning while New Sites is a long way from the finished article. But the important news amidst all the hype is that public gadgets are on the way out having created many more problems than they ever solved.
For what it's worth, my open-sourced Photofeed Gadget for Classic Sites is a novel take on the Web Widget paradigm which extends far beyond Google Gadgets and the chilly winds of corporate spring-cleaning. It is currently used on a number of active sites and the code base may still be of interest to those who want to take the concept forward on other platforms. But be warned, there be dragons in them there hills!
Here are some useful project links: