re: Orlando late July with kids (ages 7 and 4)

If you haven't been, it's not a bad drive to Kennedy Space Center as well. Probably not the best place for a 4 year old though. Do the beach when you are out there as well.

Legoland, basically the old cypress gardens with legos.

You can do the Magic Kingdom without any advanced reservations, especially if you are going for just a day. Disney doesn't have to be a planning nightmare if you are just going to check things out and just have the understanding you won't be able to do everything you want and eat wherever you want. Half my trips there are when we get bored with family and decide to do a day in one of the parks in Orlando the night before.

A lot of people who have a bad time there, just drive themselves crazy by trying to run around the park. Just enjoy the time and don't be in a rush. Pick a few things you want to do and do what you can in between that.