Todays tutorial is brought to you courtesy of @Ignatz from the lovely city of Perth (the most remote city on Earth according to Bill Bryson). He noted that Spritely (the image editor which comes with Codea) produces some fairly large and unwieldy image files. Given his background in compression he immediately worked out a way to dramatically reduce these files in size and is happy to share his coding and decoding classes.
As an example, running this compression on the images used in MineSweeper created files 28 times smaller. You can see the tutorial here: http://codeatuts.blogspot.com.au/2013/02/tutorial-26-rle-image-compression-for.html
Comments welcome as always.
.@Mark - maybe you could build this into the next version of Spritely?