Speaking of Flash, there's a free e-copy of a chapter in the Visual Quickpro Guide: Macromedia Flash 8 Advanced for Windows and MacIntosh on Adobe Labs' site: http://labs.adobe.com/technologies/digitaleditions/library/
This is interesting because the page uses Adobe Digital Editions - a new way of publishing using a pdf-style drm program. It is still in beta, but now runs on Mac OS X. It somehow hooks into Safari when it installs.
Check it out.
Update: this is one funky program. It only works when connected.... you can't download the content, apparently. It puts a 4kb ebx.etd file on your computer that manages the digital rights. If you click that file, it tells you you've already accessed it and you're out of luck. But if you go back to Adobe Labs page, you can still read the content.
When you right-click on an ebook, you get a settings dialog that can allow Adobe access to your web cam and mic....!!!
And as noted in the comments below, it's not the whole visual qp guide book, just 24 pages.