There is also schizotypal personality disorder (http://en.wikipedia.org/wiki/Schizotypal_personality_disorde...), which can look a lot like schizophrenia and can occur as a comorbidity to DID or borderline personality disorder.

I had a friend who I thought was borderline, and later suspected to have DID. She sometimes said delusional things like she thought she was an alien, or that Jesus was inside her, or that she was a reincarnated dolphin, etc. Other people told me she would get weird in conversations, a lot like the "react oddly in conversations, not respond, or talk to themselves" description in the Wikipedia article. Stuff that schizophrenic people do.

When I asked about it, she said she realized that it didn't make sense that she was a reincarnated dolphin and that she didn't know why she believed those things. Schizophrenic people don't really have that kind of self-awareness.