[Energy Field Detector]
This is just some random idea, but it would be like an electronic map, and it detects power usage/storage, might be something for PVP server to find the enemy base, or maybe finding lava sources underground
[Portable Teleportation Device]
Is linked to a PTD-Reciever (modified teleporter), when you click the button, it sends a signal to the PTD-R and teleports you to the PTD-R's location
It's energy cost would be even higher than the standard Teleporter, maybe you need to stand still for 5 seconds (or more) so it can lock on to your location and so it can charge. If a cow were to push you aside, the cow gets teleported :3. Not to forget that the PTD itself also has to be charged, since it needs to be capable of sending it's signal far enough so it can reach the PTD-R's location
[Electronic Life Support]
High energy cost device that will multiply your health regeneration by 3, and slowly removes hunger. Must be activated, for example, you're under attack know you could die, you right click the ELS and it says ELS is activated for 1 min, in this 1 min, the ELS wil monitor your body's vital signs, and starts healing you. If your hearts were to drop to or below 2 hearts, it sends out an emergency signal, wich has a small chance of fully healing you. This signal can only hapen once, if the signal succeeds, all the energy of the ELS will be drained and all the time you had left, will be removed, If the signal fails, the time you had left would be split in half or removed by 10 seconds (?)
(maybe a "Safe" mode, when it's turned on, only then it will try the emergency signal)
[Compressor Chest]
A Chest with the inventory size of a Private Safe for each compartment it holds, each compartment can be named. THe Compressor Chest is capable of storing items in much smaller spaces than they would be stored like in a normal chest or Private Safe