Okay, so these are my crappy little motivational jars that I made today. Sorry for the crappy picture quality; my room has very bad lighting and the flash didn't do much to help that.
PHOTO ONE.
PHOTO TWO.
If you can't read the letters, the one on the left says "pounds to lose" and it notes that 1 pebble stands for 1/5th of a pound. The one on the right says "pounds lost."
It cost about 10 dollars for all the stuff to make it (but only because I couldn't choose between red and blue pebbles; I ended up getting them both! Without the second pack of pebbles it would only have been 7).