All of my babies were swing babies. That is, they all loved to be in a swing from early on. Of course, I held them as much as I could, especially as newborns and infants, but there came a point where I would have to get up, use the restroom, maybe cook a meal, take care of the older children, and other things like that.
The swings we had (we went through two swings for four babies) had mobiles that contained lights and could play music, and a bucket-type seat that the babies could lay in and be strapped into.
Part of the time that they were in the swing, they enjoyed watching the lights above them, and the bustle going on in the room around them. But when it was time for a nap, or any time they got tired (before a real schedule was established), they would doze off in the swing and sometimes sleep for hours.
For several months in their first years, most of their naps were in a swing and I attribute that to several things. First, the music was always the same few songs, and I truly believe that it signaled that it was time to sleep. The melodies were soothing and I never had the volume up very loud, so they really were like lullabies for them. The swing motion was also very soothing, and it felt like rocking in a rocking chair, I'm sure. I think it also made my babies feel a part of things to be in the living room, surrounded by the rest of the family and able to see me before dozing off.
I consider a swing to be a must-have piece of equipment for new parents, because I truly think it saved my sanity....many times!