I'm not sure how I missed that. I've never heard of if hiTask! A friend pointed out Bullet Journal (http://bulletjournal.com/) too. I like the idea of having it all in your notebook but it does mean you have to carry it around everywhere.

I use one idea from bulletjournal regularly: Whenever I scribble down a note to do something later, I put a box before it. When it is done (done might simply mean scheduled into my real calender) I checkmark the box.

It is very easy to scan a page for boxes and it works everywhere. For example, on printed slides discussed in a meeting or a post-it from the refrigerator.