One enhancement for friendfeed.com I can think of is language filter. If someone who knows one language subscribes to several multilingual friends, his homepage can be messy with items and comments in languages they don’t know. Sometimes one item is followed by comments in several languages. If there is a language filter option, readers can choose only to show information in languages they know. The language filter can benefit the feed owner too. I personally do not want to bore my English-spoken ‘followers’ with my Chinese contents.
The language filter can be applied to one feed or as a global parameter. When a user subscribes to a feed, they can choose to show only contents of that feed in languages they know, or they can go to the Option section, and pick the languages they know and click OK to set it as a global preference.
A even cooler stuff is to add an auto translation feature which can translate any language in a page into one language.