We have new trailers for your viewing pleasure, all for films set to play at SXSW next month in Austin, Texas.

Know Your Mushrooms. Documentarian Ron Mann previously made Go Further, Grass, and Comic Book Confidential; now he turns his probing gaze to "a hunt for the wild mushroom and the deeper cultural experiences attached to the mysterious fungi." Featuring a "neo-psychedelic soundtrack" by the Flaming Lips, animation, and archival footage, the doc promises a "longer, stronger trip," but don't worry: its running time is only 73 minutes. In that spirit, the teaser trailer, embedded above, is only 45 seconds long.

Goodbye Solo. 'A cab driver picks up a routine fare, only to find his life turned upside down when the man he picks up asks him to take him to a remote mountaintop location, where he plans to jump to his death.' When it played at Toronto, Kim Voynar described it as "a thoughtful, compelling film," which sounds like what we've come to expect from director Ramin Bahrani (Man Push Cart, Chop Shop). Goodbye Solo has been playing the festival circuit since last fall; the trailer and four clips are available at the official site. [Via /Film]

Died Young, Stayed Pretty. Offering "a candid look at the underground poster culture in North America," Died Young, Stayed Pretty asks searching questions: How does an octopus get 'played out'? Are rock posters really the 'purest form of art that our culture has'? Eileen Yaghoobian spent four years making her first feature-length doc, which will have its US Premiere at the fest. You can buy all six of the film's posters at the official site.

I've posted one of them after the jump, where you'll also find the NSFW trailer.