I am not sure why the clipboard is so fundamental.
I have been collecting the contents of webpages in VBA from Excel where I need the contents of a page outside of the browser. It has to use IE though unless you are really knowledgeable about FireFox. If you are serious about needing the data outside of the browser - I can post the principle code that I used to collect Eurosport TV schedules off their website and filter for chosen sports. I still have it somewhere though I use a different method due to them changing their site.
Otherwise Frames and DIV layers are the best way to go. Or get heavily into server-side programming.
Flash has a few limitations. It all depends on your target audience and you cannot guess what they are doing from your own small sample of one, (and a few friends). It is anarchy out there.