See here
You said “plug-ins such as Flash that allow graphics and drag-and-drop in the browser”
Been there with JavaScript and dynamic HTML forever, just a bit hard to do from scratch – but there are plenty of resources on the web. There’s also the whole chromeless thing (www.chromeless.org) for IE as well, which predates a lot of this allegedly new technology by four or five years. The only really new thing on the block is AJAX.
Personally I can’t stand Flash because it’s too hard (and expensive) and the documentation is rubbish. It claims to integrate with databases and XML but doesn’t say how. It’s a tool for graphic designers that forces the rest of us to care about their tiny fonts, and before ubiquitous broadband it made a lot of sites (where you just want the information, not the cleverness) unusable. It’s also impossible to spider and index sites properly.
Just my two cents