No, but I let my little nephews play with my iPod Touch all the time. They love it. I still think it should be monitored, because I don't like children getting addicted to video games, plus I find I need to guide them.

As mentioned, you can block App deletion, and even if an App is deleted, you can easily restore (sure you lose data, but it's not a huge loss). I find little kids stay away from things they don't understand, like Mail, the browser, settings etc. They usually push the home button when they see the "grown-up" stuff, and want the games.

The one big issue is deleting photos. Apple should let you undo that, or maybe lock it.