I may have mentioned this in my previous rant about sleeping arrangements, but current household circumstances remind me of what a wondrous invention the infant car seat is. For sleeping. This latest kid has spent far more time in his car seat in the house than in the van. To settle or resettle him, we simply swing him a bit (see also: postpartum exercise).
And for the paranoid among us (paranoia being a category which I would have invented, had it not already existed), this is perfectly safe. He's on his back. He's secure. The arrangement has been approved by our former pediatrician, our current family doc, and the local baby nurse/lactation consultant (who confessed that one of her kids slept in his till he was 6 months old--!).
This is a very good thing.
Added benefit: if I suddenly get ambitious enough to take the kids to the library or realize we're out of milk, I don't have to wake him up to pack him along: just pop the seat into place and we're good to go. (Well, after everyone's bathroom stops, coats, shoes, etc. "Good to go" is, as we all know, a bit more of a process than the simple phrase implies.)