Jeremy recently whipped up an iPhone 101 how to on using Restrictions to set some parental controls, and we've had a peek at what Apple already surfaced in previous iPhone 3.0 betas, but now it looks like Beta 3 gets a tad more granular with an extra option:

  • In App Purchase

Along with Installing Apps, you can selectively disable the ability for you, or someone you parentally control, from impulse buying those extra game levels or custom sound systems and super-weapons.

Likely a Good Thing.