When I'm in the theater I can use it to change the music without being up at my laptop at the booth. And I can use it to turn on or off any light without having to yell to someone in the booth, or go up myself.
I like that I just plug it in at night, and it has the power to last me through the day.
It is a GPS for my car or bicycle trips.
And it impresses all the girls and gets me a lot of hot dates.