My wife and I are debating whether to do a day trip to Pompeii or Capri from Rome. I'm hearing more about Ostia Antica as well. Is a day trip to either one of these sights doable or should we just bite the bullet and spend the night down there? Help!
A daytrip is definitely possible to Pompeii - it just depends on how many hours of a particular day do you want to waste/devote to sitting on a train or bus?
If you have the option of spending a night in Sorrento then by all means do it. From Sorrento you can easily get to Pompeii in about 15 minutes on the train. Also from Sorrento you can easily take a short boat ride to Capri. Sorrento has some dramatic cliff-side hotels/scenery. It's definitely beautiful.
If you don't have the time for a night in Sorrento or don't want to sit on a train or bus and waste many hours then just do Ostia Antica.
We had the same question a year ago, and opted for Ostia Antica. We (two parents, 14 and 11 year old kids) absolutely LOVED it. The ruins are easily accessible (read: you can climb all over them; archeologists would have a heart attack). The mosaics are excellent. The museum is totally forgettable. The train ride out is interesting as well. My son is now studying ancient Rome in social studies (6th grade) and can tell them so much because of what he saw there.
Be sure to take a picnic--the experience can't be beat.
I'm with Beth - Ostia Antica is fabulous! And if you're coming from Rome, the trip to Pompeii is just a little too long. It will also probably be slightly less crowded as everyone knows Pompeii but I think that Ostia Antica is only just getting American attention.