A cool feature would be to allow multiple sub-lists within your personal to-do list. This would allow users to make lists when planning a trip or making goals for the short term, etc. Just a thought.

Easy. I do my to-do list on a pad of paper and get all the sub lists I need included there. Piece of cake.

This generation would prefer not to write, Woodchuck

If your generation considers 'writing' scribbling a list of route-names on a pad of paper then I do not think we are losing much, gentlemen. While you crusters scratch out hazy memories of the good ol' days with chongo with your feather quill pens I will be happily typing out my fresh ones on this technology that has ruined us all.

And I don't scribble. Clear concise notes. 59 cents for that pad of paper, no e-contracts, no minutes to manage, no worry about battery life or if the satellites are bounced by a solar flare. Just saying it can be simpler if one choses.