Shagley- I think they would be fine for a 12 yr old. They are real guitars. The Hannah Montana box is marked for ages 8+, and the Camp Rock one is marked 6+.
About what age would these be appropriate for? My cousin is an "immature" 12 and I know she enjoyed Camp Rock (she isn't as into Hannah Montana). She wants to learn to play guitar, but would this be too young for her?
lady_hlh- The electronics section.