As for me, it's not really important that the tailwheel is straight or the plane rolls straight. I play it by ear and use the rudder to keep the plane going straight down the runway. Once the tailwheel is off the ground, you will need to use the rudder anyway.

Here is a short video of my Kyosho Corsair taking off (1.9 MB):

[link]http://www.whitetyphoon.com/rc/kyosho_corsair/take_off.mpg[/link]

The tailwheel was on the ground for around 10-15 feet. This plane normally tracks to the left when rolling on all three wheels. Believe me, this plane is more squirley on the ground than the P-40 due to the shorter tail moment.