i've done a couple and have a friend who works on the chase crew. most of the trips are set up such that the ride is divided into two parts. half the passengers load in and when their part of the ride ends they load into the chase crew's mini van and follow the balloon to the final destination. when the balloon lands it's loaded into the trailer and everyone goes for a champagne brunch (included in the cost).
you have to get up REALY early because the balloons fly first thing in the morning (i think you get to the take off place around 6 am)-and then plan on being done around 11'ish. the views are incredible-and if it's foggy in napa they tend to come over the hills to dixon and winters (it's not unusual to see half a dozen in the air over my kid's school on fall mornings).
it is a neat experience-you can look at the napa visitors website and get the company names/prices.