I mentioned a 529 plan. We started one (actually two, one per kid) in 2004. We didn't dump a lot into it initially but made contributions over the years. For every 1,000 we have put in, the value is now 2,700. And as long as we use the funds for education, we'll take it out tax free. There are very few investments that return like that, and even fewer where the proceeds come out tax free.