I would be quite interested in these matrix keys. (and the impossible digital rain would be great)
How about taking the Simon Tam glasses from Firefly in a different colour here for a Morpheus thing, or squarer ones for the agents? Other thoughts: Telephones, important parts of the film, from mobiles to bakelite classics, etc, although hard to show as a 'matrix' phone on a key, I guess. How about a deja vu black cat to go with the rabbit? Red leather armchairs? Nm, enough brainstorming from me.