It's actually pretty easy to intergrate Sphinn and Friendfeed. Sphinn produces a host of tailored RSS feeds. For example, to Friendfeed what you're sphinning then get your sphinns RSS from your profile page. Click on the orange RSS logo.
Then all you have to do is add that RSS as a blog entry to your Friendfeed profile.
If your followers on Friendfeed don't want to see what you're sphinning then all they need to do it hit the "Hide" link.
Hopefully this will remind me to spend time on Sphinn. Not sure it'll stop me getting frustrated when people don't sphinn stories I think are interesting and keep on sphinning "5 things you already knew about H1 tags".