The folks at the ABC television series Lost are known for paying attention to detail, and it paid off on the episode seen yesterday in the U.S. -- nearly half the show was in Spanish, and it was spoken well enough to make the setting believable.
As it turns out, one of the show's recurring characters, Richard Alpert (portrayed by Nestor Carbonell) is of Spanish origin. He has been one of the show's mysterious characters, as he doesn't age, and now we've learned why. The opening scenes of the show take place at Tenerife in the Canary Islands, where the character was known as Ricardo, and the creators of Lost deserve credit for not having the characters speak accented English as might happen on other shows.
The Spanish wasn't perfect -- most of the accents heard sounded more Latin American or Caribbean than they did as being from Spain -- but it all was good enough not only to be understandable but also to be credible.
Of course, most of the Spanish is subtitled, often with loose translations (for example, "ˇAyuda!" at one point is translated as "Down here!" which is close enough in the context). What's left untranslated is of little consequence; for example, while being threatened with death, one character shouts, "ˇNo lo haga!" or "Don't do it!"
The episode -- only the first half of which would make sense to those who haven't seen the show -- can be seen at ABC and Hulu. And, of course, you can learn more about this episode from Lost at About.com.