We are driving from Toronto with kids 6 years and under. Going to strong! Museum of play. Any other fun things to do? Where to eat?
I second the Dinosaur. It is only about 4 blocks from the Strong.
You didn't say how long you'd be staying but an Erie Canal boat ride might be fun if you have the time. http://sampatch.org/ http://www.colonialbelle.com/ If you're coming on a weekend, chances are there's a local festival or carnival somewhere. Probably not much different from what you'd find back home but it's something to keep little kids occupied. A great site to check out for kid-friendly events is http://rochester.kidsoutandabout.com/