Just a couple of sites that I’ve come across in the past couple of days. Phun is a physics engine. It has to be downloaded & installed. From what I can tell, it saves in its own format.
It seems much more powerful than the physics engine for the Tablet PC, though probably more complex to use.
From what I can tell, it’s not possible to save as anything other than the native format, so you’d have to use a video capture tool to share with people who’ve not got it.
Boohbah is a very different site. To start with, it’s all on the site, there’s no downloading. It’s also designed for non-readers. As such, it’s one of the best designed sites I’ve seen, as there’s no text on there. Once you realise you have to click on things to get something to happen, well, just about every thing is clickable. I suspect some of the tasks are going to be a bit hard for the average 3 year old (e.g. some of the drag & drop), but there’s more than enough that is easily do-able. And, not having access to too many 3 year olds, they might well be better on the mouse than I am. It’s a great example of Flash!