There is an extension in Dreamweaver to Inset > Media > Image Viewer, however this doesn’t generate all thumbnails together (in the style of Flickr)...

XML Photo

The Macromedia Flash forum has a link to a tutorial at Kirupa

There’s another interesting looking one at fireworksguru which also has a full-blown forum, too.

Airtightinteractive

I think this is really the sort of thing I’m after, at airtightinteractive

This piece of kit is really nice except the .swf is all compiled , without the .fla, ...but it is free. Anyway, got a copy of this working nicely on a local machine.

In fact, as well as the new-fangled AutoViewer there’s an Admin tool, too

Scrub that! There is a way to tweak most of the parameters, and is described on the site

Macromedia

Flash Video can have custom skins