Well, I pretty much do all my take offs on PDF (ADOBE) or DWF (AUTOCAD) files on my computer but sometimes I use my ruler or my wheel pen (scale master) for lenghts and my planimeter for areas.
What I have noticed is that better tools are becoming available everyday but I don't use them If can do the take off directly from the PC. The main reason for this is because I can save my take off in a very organized way on my PC. Very acurate and quick.
For instance, If I'm measuring an area I can do it on PDF. I can mark my measuring area and I can always go back and see what I measured before, really quick avoiding the need of re-doing the take off to see If did it right the first time..