K.S.
When my youngest son was three to four months he would only sleep a couple of hours at a stretch unless he was in his swing, too. In his swing he would sleep for five to six hours. After talking to our pediatrician, I would actually let him stay in his swing until he woke up and demanded to be fed. (He had reflux and apparently the upright position was easier on his tummy.) I would wake up as soon as he started crying, then I'd nurse him and put him to bed in his crib. It worked like an absolute charm and it was SO wonderful for me to be able to sleep for four or five hours in a single stretch. He's ten months now and he's been going down (in his crib) at 8:30 p.m. with absolutely no problem for about the last four months.