For my Red Alert Zero mod;
The "Intel Stations"- the Allied Uplink Station and the Soviet Psychic Sensor;
Both available at Tier 4, these structures greatly enhance the intelligence-gathering capabilities of the commander that wields them;
The Allied Uplink station connects to numerous surveillance satelites- notably an orbiting Spy satelite. When summoned, the sateliet casts a large sight radius that can be controlled and moved to any location- effectively a large mobile 'eye'. The satelite takes a while to swing into nearby orbit and can maintain a geosyncratic position above the battlefield for a short time.
The station also enhances the Air HQ's "Surveillance UAV" by allowing it to reveal hidden units.
The station itself has a huge sight radius.
The Soviet PSychic Sensor generates a large field of psionic signals capable of reading the minds of any non-robotic unit ordered to move or attack the area nearby the Psychic Sensor- revealing both the intended target of the unit, and the psychic link toward the unit itself. Note that spies and stealth units cannot fool this sensor.
Also, the Psychic Sensor augments the Radar Tower's "Radar Sweep" to also detect hidden units.
Design-wise, the Psychic Sensor is based quite closely on the original RA2 concept art- feeling there wasn't much needed to be changed except some minor details (the spinning rods being the main ones).
For the Uplink Station, I was tempted to use elements of previous designs I made- but decided something a little newer- and added one of those 'buried pit' style satelite-dish to the mix, and built around that.