A well-written manual and a few snap-together models provide a good conceptual understanding of how DNA and genetics work. Some of the hands-on activities seem like nothing but busy work; others are invaluable at getting kids interested in the process of scientific experimentation.

One experiment takes you through the process of isolating DNA from tomatoes. Adult reviewers found it more difficult than the manual let on -- which probably means that a kid should have no problem. You can also breed bacteria and then do some genetic engineering on them, but be careful -- under the Patriot Act this stuff can get you thrown in jail.