You might want to consider a 529 plan. There are two basic types; college savings which in a sense prepurchase college tuition, kinda like a cemetary plot, or a college savings plan. Check and see where these kids are going to college, then figure out which one fits their needs the best. These plans vary from state to state. Be sure to see an expert. The one piece of advice I can give you is that since these kids are almost of college age, do not put it into a savings plan where you may lose any of the principle.

__________________
You don't need a weatherman to know which way the wind blows - Robert A. Zimmerman