There's an old story I heard in the Navy about an experienced carrier pilot who got a bad cat shot and had decide whether to eject out of a perfectly good airplane before the end of the catapult stroke (<2 seconds), lest he start a sink rate off the end of the bow which would quickly put him out of the safe ejection envelope.  The decision had to be split second and once made (obviously) there was no turning back.  He ended up safely ejecting.

When asked by a squadron mate, "When did you decide you had to eject?" the reply was, "A few years ago".

The moral of the story is that situations like this happen in the blink of an eye and absent suffiecient airspeed and altitude, you really need to have thought out your plan of attack before you ever start your takeoff roll.  I like Mike Easley's idea of establishing a no turning back altitude at any given airfield.  But as Hamid said, the decision to turn or take a path which will likely sacrifice your airplane is one that needs to be thought out before you even get into the plane.  An engine failure immediately after liftoff in any single engine airplane simply doesn't afford pilots the luxury of time to consider what to do.

Having a plan before you take off and then sticking to it will inevitably increase the odds of survival.

Skip Slater
N540ES