Well I've looked and looked and just cant find data on the max current of the 5 v output (or even a suggested reasonable max) They all mention 50 mA for the 3.3v output. Looking at the chip it's a smaller board than the Arduino Uno so I don't want to pop it. I assume someone will know the max current that the regulator on this board can handle and surmise what the 5v current out could be? Thanks in advance!
EDIT: The regulator / board 5v pin out, not chip related.
EDIT: Assuming supply is from the 12v power adapter.
The schematic shows a NCP1117ST50T3G. The datasheet shows 1500mA (typical).
Note that you may not actually be able to draw that at the higher end of the input voltage range since the Arduino may not provide sufficient heatsinking, needed since the regulator will shut down if it gets too hot (and the regulator will melt down if it doesn't shut down).
Also note that the traces on the board may not be designed to allow that much current to flow safely, and you could end up damaging the board itself regardless.