Already a PCB mistake and the boards have not even been delivered yet. Luckily it's a purely cosmetic one but I'll mention it here to hopefully keep others from repeating it.

I used PCB-pool for the first rev of the boards since they also throw in free stencils if you order 10 boards or less. If you order 11 you will be charged $90 for the stencils, I don't quite get that one...  Anyway, 10 boards was just fine with me so I placed the order. Normally I use gerbers for transfering the file but they charged extra to process standard gerbers so I used their Altium file option. Sending the PCB source file to a board-house has always made me a bit twitchy but this will be open sourced eventually anyway, so what the heck I though.

Altium has no good way of putting artwork like logos on a PCB so the standard workaround is to stick your logo in a truetype font and print it as a character on the PCB. Well, the font was apparently not embedded in the source file and since the board-house does not have the same font it's obviously not going to print correctly. That is why I have a big lowercase "m" on the board. 

Oh well, live and learn.