Baby swap is great, depending on your situation. And, it can differ from ride to ride. In general, at the entrance to the ride (at the BEGINNING of the line), you tell the CM you are doing babyswap. They give the person who is riding some swap tix (usually good for 3 or 4 people). The person holding the baby goes to get a snack and meets the riders after the ride. Then, the non-rider drops off the baby with the rider and then rides w/o the baby through the fastpass line. You can take people with you (whatever the swap ticket says) so you don't have to ride alone.
The swap is done at different places on different rides. For some rides (like Splash mountain and Thunder mountain), you wait completely outside the ride line. For other rides (Star tours, I think ??) you wait nearby and then swap just after your other party rides. Just ask.
ALL of the CM's know about baby swap. Just ask at each ride! For us, it meant that a couple of the other kids got to ride 2x! They were happy about it! It does take a lot of time to do the swap, but at least all of the adults get to experience the attractions and no one resents waiting!!!