I keep wanting to like and use FriendStream, and tried it for my first couple days with the tbolt. But it's so limited on what you can do in the widget, and once you open the app it's just a substandard Twitter client at that point.
Right now Tweetcaster is my favorite Twitter client, and the stock Facebook app is my favorite for that, although I'm much more of a Twitter than Facebook user.
If you want an integrated Twitter/Facebook client, try Hootsuite for Android. I haven't used it because as I said I'm not a big Facebook user, but that may be worth a shot. (and it's free)