LDMs have been around for a long time.  As they evolve so does their complexity.  They are able to do more and more calculations.  Personally I just need a simple unit that gives me measurements and calculate area and volume.  The TLM65 is that unit, it is compact and easily fits into any pocket.  I carry it around with almost everywhere.  It measures up to 65 feet with a + or – of 1/8″.

It has a simple 2 button operation just hit the on button twice and it will measure.  Below that is a button that will calculate area.  The unit will automatically shut off when no buttons are pressed.  The big LCD screen is not backlit and the unit is power by a AA batteries.  Check out the Stanley TLM65 on Amazon.  This tool is great estimators, realtors and just about anyone that needs to measure areas up to 65′.