Add the ability to do math calulations when inputing values into text fields.
For instance, in the Information Window, you could rotate an object in the x axis that is already rotated 57.36 degrees to 60 by typing "57.36 + 2.64" into the Rotate X field and hitting return.
Even better would be higher level equations such as "(60 - 57.36) + 57.36" to get the same result without know the 2.64 bit.
Another use would be to create a circle with a circumference of 15 by typing "15/(2pi)" in the radius field of the Attribues Tab.
Or you could scale a 34.8 cube to 20 by typing "20/34.8" in the scale field.
Many programs such as Adobe Illustrator and Maya offer similar solutions.