A Scanner Darkly

Phillip K. Dick's story 'A Scanner Darkly' is a story about drug adiction. For the moment it can be found at Peek Vids in three parts (here, here and here). It is well worth watching, especially if you've seen some of Richard Linklater's other work (such as Waking Life).

Warning, it won't be up there for long, I suspect, so if you want to watch it do so quickly.