I just upgraded to Adobe PDF Reader X (10.0.1), and when viewing PDFs in a web browser it shows them in a new 'Read Mode' by default.
This 'Read Mode' doesn't show a toolbar (Save, Print, etc in a nice menu at the top of the PDF), but instead has a limited menu that fades in and out when the mouse nears the bottom of the displayed PDF.
I spent a couple of minutes finding and setting up the toolbar the way I wanted it, but it didn't save my preferences the next time I opened a PDF in Internet Explorer 9 - and I've been through all of the options in the 'Page Display Preferences' and can't see any reference to 'Read Mode'.
If I open a PDF outside of the browser, then the toolbars are shown by default! That's what I'm after, but in-browser.