The problem with 529 accounts, as I'm discovering, is that the investment options are limited, and there's assorted fees.
I'm 24, and will probably have kids someday, so I've got a general "potential future offspring" account that consists of 2 USAA mutual funds. I have $125 automatically deposited there monthly. I also have a 529 plan through USAA, but it turns out it's just in partnership with UPromise or something. $50 a month gets deposited there. It has existed for 4 months, and although I deposited $200, the account value is $189. I am thoroughly unimpressed.
Although the earnings are taxed, I'm doing much better in my self-directed accounts. I'm beginning to wonder if 529 plans are a bit of a fraud, designed to prey upon well-meaning parents.