Hooking up Drupal and Flash
You can make an entire site in Flash and use Drupal as a back end using Drupal's Services module, but to make it easy and secure is a pain. But seeing as you're using Drupal as a framework for the data, why not also use a framework for the Flash end of things - this is where dp+dk step in.
Here's a link to a blog post that should get you started: http://bit.ly/7b8oit
dp+dk have created a whole bunch of classes that enable you to connect to Drupal using all the security available, sessions, api keys etc - which should allow you to get and save stuff from Drupal with peace of mind.
The best way of getting all the classes working is to use SVN to install all the code, here's the link for that:
There's a tutorial on their site, whats not so well documented is that you can extend their DrupalService and DrupalEvent classes to hook up to any custom Services you might make.
The whole thing works with AMFPHP so its really quick and very easy - saved me a lot of time.
I'll be expanding on this when i've got a bit of time - bug me if you want it sooner...