There is a widget, but no official app
I believe Hermes or Mauku (apps) take care of Facebook
Thanks but neither Hermes or Mauku offer what I asked. Hermes merges your contacts information with the same contacts in Facebook. I tried it when it first came out and it practically ruined my address book.
Mauku is simple a twitter feed client (and there's no option to link to Facebook).
I'm just surprised that no one else seems to be complaining about the lack of a proper Facebook app and why no one has developed one. Surely, it can't be that difficult and it's been over a year since N900 came out.