You mean like a bookmarklet? Manage > Goodies has a bunch of browser-specific hacks to make the RSS button go to NewsBlur. There's also a bookmarklet that lets you add a site to a folder (and create a folder if you want) from the site itself.

Hah, now all you're missing is a feature to erase 6 years of muscle memory and habit to always immediately check Reader.

Excellent, thanks, I think that would probably do it. I was thinking specifically of that screen you'll see that lets you choose whether to add something to Reader or your home page.