Speaking of on-location, here's a shot of a landing party" prop used by Dr. Valerie Young in POLARIS. It was built from an electronic toy and modified to include a greenscreen element for VFX superimposition (a reflective surface was placed over the greenscreen when the device was "idle") and custom interface graphics.
This photo of the same prop was taken before final touchups to it. The rubber band holding the scanner disc in place was there while the cement dried.
I really liked this prop because it looks so unlike a tricorder. The offset circular screen is what really does it.