Random things, not sure if they are mentioned already
Wireless Transmitter & Receiver -
These can be hammered into different generic shapes (and will display a color related to the colors of wire connected to it). They will send/receive signal to other objects within a fairly modest distance, as in a triangle shaped transmitter signal will only be "accepted" by a triangle shaped receiver. The transmitters will only emit signal based on color of wire connected to them, and the receivers will only accept signals for the colors of wire connected to them.
Perhaps 2-3 tiers of them, with the highest tier covering a huge range on the map.
Repeater Switch/Pressure Plate/Lever -
This object will continuously (every few ticks) send signal across connected wire as long as it is toggled on (switch & lever), or as long as it has an entity standing atop it (pressure plate). This particularly to save time/space for builders that use elaborate Bird Trap designs to accomplish something similar.
Macro Recorder -
This handy little block, when activated by a Red wire, will record the next single interface action. Then, when activated by a Green wire, it will repeat that interface action. Any other color of wire will clear the stored interface action. And by interface action, I mean along the lines of "quick stack to nearby chests" or "un/assign NPC from house".
Mostly because this kind of block would save a lot of mass-clicking that I do running through my chest storage room - or you could set up a convenience for these by building a house in the jungle, and upon pressing the plate/switch, it would automatically move the Witch Doctor into it (and if done from far enough away you could save yourself a minute or so doing it manually at night to move him there quicker).
Any interface actions recorded by this that would place something in the trash will also record what type of block/item was trashed and attempt to trash just matching blocks, for instance.
Turtle (?) -
From the Minecraft FTB/mods, primarily a lite command-line API for them (eg: dig 5 10, digs a pit 5 tiles wide and 10 tiles deep; tunnel 3 30, digs a horizontal tunnel 3 tiles high and 30 tiles wide). Turtles themselves would have a small 3x3 inventory with which to place/build things somewhat autonomously using whatever blocks it has in it's inventory (eg: build rect 30 30 fill , builds and fills a 30 by 30 square, build circ 30 60 nofill, builds a circle within the rectangle of 30x60 and doesn't fill it).
Distribution Chest -
When activated, it will distribute it's contents to other chests connected to it by wire. Sort of like the Macro Recorder but perhaps a little more balanced as a on-stop-drop off point to dump your junk, push a button, and let it sort itself out.
Requester Chest -
The opposite of Autosorting Chest, would have an input for you to type (or place?) a block for it to retrieve from chests connected by wire. The retrieving activated, of course, by signal.
** The above two to allow for distant/hidden treasure caches that you could still deposit into and retrieve from.