I've seen that film, it's rather good.I'm not sure about books but a film called The Quiet Earth is one of my favourite such movies. I believe it was based on a book/story by an Australian author Greg Harrison.
I just read 'The Postman', it was OK but to me it seems fairly tame and watered down. Was a fun read but (IMO) not someting I need to re-read.I too am a fan of Brin's book; The Postman. Enjoy!