The online streaming and DVD rental service Netflix now has a small selection of Peanuts television specials available via the Instant streaming feature. They include:
A Charlie Brown Valentine
A Charlie Brown Celebration
Charlie Brown's Christmas Tales
Happy New Year, Charlie Brown
I Want a Dog for Christmas, Charlie Brown
It's an Adventure, Charlie Brown
This is America, Charlie Brown: The Mayflower Voyagers
You're a Good Man, Charlie Brown
Note that the best known specials, such as A Charlie Brown Christmas or It's the Great Pumpkin, Charlie Brown, are not available on Netflix Instant streaming. However, they and many other Peanuts specials are (and have been) available from Netflix as DVDs.
This is the first time that A Charlie Brown Celebration and It's an Adventure, Charlie Brown have been made available in a digital format as far as I know; they haven't been released on DVD in the United States or on other online services.
Many Peanuts TV specials are also available as digital downloads from iTunes or Amazon Instant Video, although they are only available to buy, not as cheaper short-term rentals.
Thanks to Jeremi Smith for the tip!