Dirkhens:
Will using one cable for the common effect sensor input? I'm talking 3+ arduino's in link here. Can test it myself but if any of you know! You guys are a blessing from the gods.
daisy chaining 3 Unos together wont work. The problem is the monitor will not know which Uno is supplying which bits of data, and if 2 are transmitting at the exact same time but one is a 0 and the other is a 1 the computer will only see the 1. Going through a hub will allow simultaneous data transmission. The other way to make this work is to have one Uno set as a master (with the sketch) and the other 2 as slaves. The data would be through the I2C bus into the master and out the USB to the serial monitor. I don't know how to write the code for this but I have seen it done.