Setting up an investment for the kids

I'm due to have my first child in March, and looking to start putting money away for when they're 18 (or probably older and more responsible). As far as I can tell there aren't really any good tax-beneficial investments to slowly save? If I start with $5000 and put away $100 a week at 10% (just put it in the index) will be around $300k by the time they're 18... put this in the wife's name for tax purposes as she doesn't work right now.

Is there anything better I can do or is this pretty much the limit of my options?