Most of the TinyDuino boards themselves are designed to be either square or round - a square version can be made round by just cutting off the corners using a small handheld cutter, then can be filed by hand. Some of the newer boards (like the Bluetooth, WiFi, etc) will not be able to be rounded, but most of the core ones (like the processor, USB, Protos, LEDs) can be made round.
We originally were going to sell these in either a round or a square version, but realistically we determined that the mounting holes and screws to hold the boards together are needed in most applications where there are a few boards stacked together.
Thanks,
Ken