I bought a bunch of these and was kinda MEH on them. Last night I figured out what they were born to do. If you have to proto a project where you have a 2x3 or 2x4 cable incoming, solder male headers on each side and break that .1 spacing out to the .4 spacing you need to bridge the breadboard gap. Love it. LOVE IT. Best $.50 on Sparkfun once I figured that out.

Note that the edge and borders of this board are metal, forming a single conductor top to bottom and around.
I find it rather inconvenient having to worry about shorting bare leads and wires.

I bought a few of these after reading the comments (and there are some really great ideas here! The 2-led module from Dragon99 that slips on pin 11/12 for a quick indicator setup is amazing.

I copied his idea then came up with an ICSP / 6 wire gender changer. Has 2 female 2x3 pin headers, and 1 2x3 male all wired together in ISCP format. So you have male to male, and female to male changers on the board, since I only have M/M and M/F jumpers. Hook the female to the ICSP header on board 1, jumper to the board into the female connector, then use the female header to the male end of the jumper, and the female to the other iscp header on board 2. Worked well!

These are awesome! I only ordered a few of them to try, but now I wish I had bought a bunch when they were in stock. The first thing I made was this. Two LEDs to hang on Arduino pins 11 and 12, nice when I just need a couple indicators for something. I project many more tiny but useful projects like this.

I found these to be absolutely ideal for making snap-on voltage regulation modules. Some headers, capacitors, a voltage regulator IC, and this to make a power supply for a breadboard or other prototyping device. Reduces the visual complexity of my prototyping space and I no longer have to keep recreating the wheel between projects.

Please make more sizes of these things. I would love to have something like 20x20 or 15x15. In the sexy red obviously.

These are great! I randomly purchased a few of these last time I placed an order just because. And I used all of them for extremely us full things! I mean they are super dinky (5/5 as shown) but they really come in handy.

I created 2 custom 'dead bug' breakout board for two differnt SMD chips I had (I glued the chip down unside down and ran wires from it, then soldered one head to the board which allowed me to place a second board ontop, sandwiching the chip and then I put headers on the top board and connected them to the wires, then I filled the 'sandwich' with hot glue, incasing the SMD and securing the connections. work great.

I have also made other break outs for cables.

Dont expect to have a whole circuit on this thing (unless you make floors).

USB Connector BoB!

It doesn't look like it has any copper??? on it. How are you supposed to solder to it?

What do you mean by "creating 3D prototyping shapes?" If I made 3D electronic prototypes, I would look for a cube-shaped protoboard.

It would be good if they made fully white versions of these series so we can mount LED's and not have a colour shift.