The firmware for a project I'm working on using an enhanced mid-range device (a 12F1822) would most easily coded using two tasks so I decided to see how simple the code would be. The results are documented here http://www.pic-projects.net/index.php?option=com_content&view=article&id=67:simple-multi-tasking-on-enhanced-mid-range-devices&catid=51:multi-tasking&Itemid=77