Our new summer commuting habit: I bike to work, my husband rollerskis home. We work in the same high tech park. With the car, my husband drops our son off at daycare on the way to work, and I pick our son up on the way home. I have negotiated reduced work hours (for less salary), so I leave work an hour before my husband.
I'd like to go all-bike, but my son goes to a daycare that we can only get to via a busy road. For the one year more that he is there, there will still be one car involved.
This half-commuting by bike plan could be a useful idea for other people too, if they have a friend at work who lives in the same neighbourhood. It could be really useful for somebody who finds their work a bit too far from home to fit in a bike commute both ways each day.
It also means there is a car available, to do those occasional lunch time errands, or in case there's a big thunderstorm after work.
You could pool three or four commuters with one car just as easily, with a bigger bike rack.