Another option in Destin is Under D Sea. It's on Commons Drive behind Bealls. They have a drop-off program, and are pretty flexible (1 day/week to 5/week). I'm pretty sure you can also just take the kids on an as-needed basis -- nice when you need to go shopping in Destin, and it's fun for the kids. They just changed their hours, though, so I'm scrambling for part-time afternoon care for my 2-year-old.
Thanks for all the info! I've been calling a lot of the places you recommeded today...