The L298N has a voltage drop of between 1.8 and 3.2 volts @ 1A, so you're going to need more than 3V drive to the L298N motor supply anyway. There's not much point in using a regulator for the motor supply. I would use 3 or 4 AA cells and no regulator to provide power for the motors, and a separate supply for the Arduino.
Doesn't the L298 gets it's power from logic 5V supply?
As far as I know, the L298 does not draw power from the motors Vin. I measured the Vout for all outputs and I get 3.10 - 3.20 V (@ 3.2 ~ 3.3V input) so as far as the measurement went I didn't notice any voltage drop.
So... is there something that I'm missing ?
I have a separate 9V battery to power the Arduino.
My point to using a 3V regulator is to not kill the motors ahead of their time... at least that made sense for me when I chose this path.
@James C4S: using only 2xAA is not a viabile option because the 2 batteries don't provide the necessary current to drive the motors... (tried this option:D )