Sorting. I like to sort things. It's not my favourite thing in the world, but if I've got nothing else to do, sorting keeps both my mind and hands busy while being simple and relatively quick and varied, and sometimes I end up with something that's better than a mess, practically speaking.
I used to sort my trading cards all the time. I'd usually sort them based on type or colour, but also sometimes by other attributes. Nowadays, I sort the dishes as I empty the dishwasher for my parents and I organize my games alphabetically by console. It makes it easy to find what I'm looking for.
EDIT: Cooking is considered a menial task, too? I love cooking, especially since it lets me try stuff and learn new things, and I get to enjoy the results of my work.