After reading the thread about leaving a baby for the first time I was curious as to what others have done in this regard. I now realise that there is likely to be a variety of thoughts on this, so please keep it nice - hopefully we can provide our own experiences without being judgemental about other people's experiences (or am I being naive?!?).
In my case, I left DD with my DH very early on for short periods of time - I think the first time was when I went to a post-birth physio class run by the hospital when she was about a week or so old. After that, I would regularly leave her for an hour or so while I got things done/went for a walk etc. In our case I think it helped my DH find his feet as a new father and feel more confident in his parenting abilities. And for me, it meant a much needed and appreciated break.