If you can believe it, the Barrow-Downs actually appear in
two films - they're also in the Finnish adaptation of LotR,
Hobitit! Well... sort of. They're more sort of Barrow-Woods this time through.

(
Larger version)
The Barrow-Woods -- Frodo threatened by a disembodied glove twirling a baton
Pippin and Merry in the wight's clutches -- Tom Bombadil banishing the wight
This version weirdly cuts Goldberry and the whole House of Bombadil, so Tom rescues the hobbits from Old Man Willow, then abandons them in a swamp after telling them to be more careful. He shows up again out of nowhere to deal with the wight, then once again just leaves them in the middle of the forest.
All of this is in Episode 3 of
Hobitit, along with semitransparent Black Riders and the Wild West town of Bree. I'm doing another pictoral summary (much easier this time, as it has English subtitles!), so you can follow along
here if you like. Six episodes to go!
(Be advised that Episode 1 has a
lot of adorable hobbit children. I have a whole Appendix A of pictures.)
hS