Another thing you might think about is the use of digital frames for is props like the tricorder. The small key chains can be inserted in small hand held dummy props, and they are fairly cheep. Stargate Atlantis used to used old Palm Pilots in some of their hand props. Some were for displays, some were rigged to use the light to back light a static image overlay.
You could work the key chain frame into the one of the arms of the captains chair. But that may not have any real practical value. Take a look at this thread I recently found for some TOSmovie era ideas...
Check the entire thread out. Lots of kewl stuff.