The production of Lost filmed three different endings to last night's Season Four finale as a means of confounding any spoilers and sneak peeks. The NY Mag has some video screens.
There were three endings, one real and two alternate endings filmed for the Season Four Lost finale in an attempt to keep the real ending a secret.

Dharma Initative

In 2001, after Stuart Radzinsky's alleged suicide in The Swan, Kelvin Inman, a man who found Desmond adrift on the beach, was still working for the Dharma Initiative in the Swan station.
Lost producer Carlton Cuse confirms in a podcast that Kelvin was indeed a member of the Dharma Initiative.
In the "Lost Experience", an actor portraying fictional Hanso Foundation executive Hugh McIntyre appeared on Jimmy Kimmel Live, where he stated that the Foundation had stopped funding the Dharma Initiative in 1987.

However, in season 2, an air drop of supplies arrived for the Swan station. As an airdrop would require a cargo plane, pilots, parachutes, a loadmaster, and the supplies themselves, this would suggest someone is still providing funding for its activities.

Video: Lost

The series uses pop culture songs sparingly, and used a mainly orchestral score (consisting usually of divided Strings, Percussion, Harp and 3 Trombones.)

When it features pop songs, they often originate from a diegetic source. Examples include the various songs played on Hurley's portable CD player throughout the first season (until its batteries died in the episode "...In Translation", which featured Damien Rice's "Delicate), or the use of the record player in the second season, which included Cass Elliot's "Make Your Own Kind of Music", and Petula Clark's "Downtown" in the second and third season premieres respectively. Two episodes show Charlie on a street corner playing guitar and singing the Oasis song "Wonderwall". In the third season's finale, Jack drives down the street listening to Nirvana's "Scentless Apprentice", right before he arrives to the Hoffs/Drawlar Funeral Parlor, and in the parallel scene in the fourth season's finale he arrives listening to "Gouge Away" by Pixies. The third season also used Three Dog Night's "Shambala" on two occasions in the van. The only two pop songs that have ever been used without an on-screen source (i.e., non-diegetic) are Ann-Margret's "Slowly", in the episode "I Do" and "I Shall Not Walk Alone", written by Ben Harper and covered by The Blind Boys of Alabama in the episode "Confidence Man". Alternate music is used in several international broadcasts. For instance, in the Japanese broadcast of Lost, the theme song used varies by season; season one uses "Here I Am" by Chemistry, season two uses "Losin'" by Yuna Ito, and season three uses "Lonely Girl" by Crystal Kay.

Be aware

The DHARMA Initiative conducted research and other activities on the Island in a number of stations. They all have (or have had) power (from an unknown source) and a water supply as well as various kinds of equipment (e.g. machinery, living quarters, computers, medical equipment, etc). Each facility also has its own octagon-shaped logo, utilizing a different symbol to designate which station items or personnel correspond to.

There are several recurring elements and motifs on Lost, which generally have no direct effect on the story itself, but expand the show's literary and philosophical subtext.

These elements include frequent appearances of black and white, which reflect the dualism within characters and situations; as well as rebellion in almost all characters, especially Kate; dysfunctional family situations (especially ones that revolve around the fathers of many characters), as portrayed in the lives of nearly all the main characters; apocalyptic references, including Desmond's pushing the button to forestall the end of the world; coincidence versus fate, revealed most apparently through the juxtaposition of the characters Locke and Mr. Eko; conflict between science and faith, embodied by the leadership tug-of-war between Jack and Locke.