Option 1: Subscribe to single aggregated feed from FriendFeed using the URL http://friendfeed.com/name?format=atom – do remember to substitute the word name with your own (or someone else’s) FriendFeed login. See example.
Option 2: Export all services, that you have added to your FriendFeed account, as an OPML using the URL http://friendfeed.com/name?format=opml [see example]
In the first case, all your services will get syndicated as a single aggregated feed via FriendFeed but in latter case, your favorite news reader will have to directly fetch the content from the original source. Pick the one you like. Thanks Bret Taylor.
Related: FriendFeed Tips and Tricks