Yes, Desktop Command Execution widget is particulary useful to monitor things. I personally use it to monitor max and min cpu freq, free memory and RAM, battery current draw (and detecting charge), battery temp...you can execute the script by clicking on the screen or execute it every x seconds, minutes or hours.

Btw, you can use icons for scripts to control / adjust volume during calls (as it is not yet implemented in Leste), or adjust brightness in the dark, or adjust cpu freqs by hand and more. ( Desktop Cmd Exec widget can be used as well)