Kara I have wondered this same thing many times! I like that "learning by living" as well - a good way to think about it!
We do very little on Mondays and Tuesdays. And Fridays. And most afternoons.

But before the snow we really did have a much better "outings" schedule and I hope that we are able to get back into it in the spring, that the winter hasn't made me lazy.
The reality here is that in the mornings I sit on the floor and let DS dictate what we are playing. Which is everything from Little People to play kitchen to colouring, to DVDs (which means getting all of the DVDs out, him choosing one, pushing the buttons on the DVD player and then changing his mind. So we can play DVDs for an hour without actually watching any of them

), to playdoh, and so on. When he does get into something I leave him but he lasts 5-10 minutes before dragging me back.
In the afternoons we tidy up and do some house work and get dinner ready - he'll play in the kitchen sink full of water or stand at the counter and throw veggies or dump a bag of rice on the floor (ie/ help mommy) but that's really it - there isn't much time from the end of his nap at 230 until we eat dinner at 430 so it's pretty frazzled.
I make sure we go into town one morning a week, we go to the pet store, have a run around the mall, maybe sit in the bakery and have a snack, and chase the pigeons around the town square. We used to do this like 3-4 days a week but with the weather, no.
We only have one playgroup during the week

So at home, no....we are very unstructured and I don't plan much out. I would like to, I think I should, as we are both getting bored, but don't know where to start, kwim?