Trevor,
I've been very busy with all that budget stuff these last few days. It is hard to pick up the thread of Division 1 (IV) of Being and Time after all that.

So let me come back to the question I posed in the previous: how do we encounter other people in everydayness? After all, it is only in a world of others that things can be deemed to be useful at all. So how do we encounter others?

In Being and Time Heidegger says that being along is a deficient or defective mode of being. That implies that everydayness a communal world of being with others.

As Heidegger says 'the world is always already the one that I share with the others. The world of Da-sein is a with-world. Being-in is being-with others.' (§26) Heidegger's category of 'das Man' ('the they') defines the average which directs the way each of us lives. It implies that only by having agreed public practices that it is possible to live in the world at all. Without shared average comportment there could be no referential whole, no public world. What Heidegger is arguing against is an individualist conception of society as a collection of individual subjects' worlds.