take one start URL.
feed that into an XFN spider:
save the OPML to disk.
start your favorite RSS reader and import that OPML file. it helps to have a reader that understands folders of feeds, and on clicking the folder itself, shows a combined view of all feeds in that folder. i use brief for firefox.
boom! your RSS reader is now an activity stream reader, without the Social Network Fatigue! i did not enter a single URL beyond my own. my friends' pages provided their own RSS feeds.
want to add a 'ghost friend'? just add a feed as normal. Dont think friendfeed updates fast enough? Its your RSS reader, tweak the settings!
downsides are most RSS readers keep their data on the local box so if you move between a desktop and laptop frequently, they wont be in sync.