FriendFeed Language Filter 0.1
This is my first Greasemonkey script, you can check out its project page. Here is a quick screenshot of settings (languages):
I think this quick helpful to me, although it doesn't work perfectly, it may miss some entries because of detection is not complete.
Before I wrote this script, I was trying to write a script to make iPhone interface of FriendFeed can auto-refresh. I planned loading iPhone interface in Firefox's sidebar, but I realized that Greasemonkey can't work with pages in sidebar. So, I moved onto my next desire for FriendFeed, which is Language Filter. I had this idea for about two weeks ago, now I can enjoy more feeds! 
