Presumably you have some code roughly equivalent to this:
if key(right): Xvel += 3; if key(left): Xvel += -3; if (Xvel > 0 && !(key(right))): XVel += -1; if (Xvel < 0 && !(key(left))): XVel += 1; [/CODE] Those being rightward acceleration, leftward acceleration, rightward deceleration, and leftward deceleration, respectively. What if you just changed the speed that gets decelerated to, so it's something higher than 0? That way you can stop or move left if you want to, but left alone, your horizontal speed will default to something positive.