If you missed Extras, the final episode/Christmas special, as I nearly did (the only thing I wanted to see over Christmas - well, that and the new Oliver Twist) you can still watch it for another 6 days on the new BBC iPlayer. It's absolutely brilliant. I even want to use an exclamation mark! There! That's how brilliant it is! Oliver Twist is on there as well: I watched it all in one go overnight, when that was repeated on sign zone.
Update: You can watch everything broadcast by the BBC in the last seven days on iPlayer. (I think it only works if you're in the UK. Can anybody confirm that?) In effect you don't need a television anymore, and you can do your own scheduling. However, there is something good in the feeling of watching a brilliant new production "as it goes out", and knowing that many others are too.