I listened to this episode of Radiolab on CRISPR last night (great episode, everyone should listen), and I couldn't stop thinking about this part discussed at the end of the episode about a CRISPR gene drive... the idea is, you might want to replace some gene in a population, so you might use CRISPR to edit the gene of a single parent. Then that parent might reproduce, and there's a chance that its child might have it in the population. Natural selection whether it stays or not... it could, very well, peter out of a population.
But then they talked about this idea, which apparently worked on yeast "on the first try", which was to have the parent modify the yeast of the child during reproduction. The parent includes the instructions so that in reproduction, it goes through and edits its new child's DNA, and inserts the instructions on how to have that editor in the child's DNA too.
Holy crap, am I wrong or is that a Thompson hack in DNA form?