eXistenZ

In eXistenZ, there is one broad point that I believe Cronenberg is trying to get across: humans have become so reliant on technology that we can't tell the difference between our virtual, avatar selves and our real selves. When people nowadays go on Facebook or Twitter, or any one of those social networks, they believe that that is their reality. They get sucked into an online world and are mentally removed from the real world. This happens in eXistenZ, but in a more literal sense. Through the example of virtual reality video games, Cronenberg shows how new technology can be an escape from reality. In eXistenZ, the pods are "living" video game consoles that plug into humans and use their energy to power the game. The humans then play the video game and are put into a virtual world that is so realistic that it becomes difficult to distinguish between it and reality. This is analogous to our use of technology, since we become removed from reality and treat our virtual self as if it were our real self. It becomes an addiction, as it did in eXistenZ.
The fact that the "living" pods use humans for energy blurs the lines between humans and machines because the pods use the humans like a parasite. The fact that the pods are using real animal organs, but aren't alive like humans are alive (in the sense of emotion, communication skills, etc.) further blurs the line. However, it seems that they strive to be an actual living thing. And, in eXistenZ, the humans treat their bodies like a game console (which only furthers my belief that Jude Law is actually a robot). They use their body like a machine, which dissolves the human-machine distinction even more.