FYI: Touringplans.com has a special touring plan for one day visitors who want to see all the Harry Potter stuff with a one day park to park ticket. They also throw in a couple of other highly rated attractions (good choices actually -- we get in our favorites). It's a six dollar cost for an annual subscription to their Universal plans. Given that a one day park to park ticket for one person is $136 before taxes, I did the $6 investment to make the most of our day. It's also nice to see their predictions of what line waits we'll be. We're going at a low crowd level time, but waits will still be long for Gringotts and Forbidden Journey. Still it didn't look too bad and helped me decide that a one day visit would be worthwhile and that for what we are interested a one day visit will work well for us.