If it's a side project, you have to ask yourself what kind of side project it is. If it's a business or something you want to turn into a business, just take any task that takes longer than an hour or two, put it down on a notecard or sticky or some digital equivalent thereof, and put them in a priority queue. If it's just for fun, don't worry about it--if you're not frittering away on things just to please yourself, why are you hacking anyway?