Quite by accident I left my youngest son's 2008 Coverdell deposit in a Money Market account rather than putting in the right fund. It's been sitting there making about $23 over the last year. I figure Obama is finally right about something - this is a great time to invest, so I moved it yesterday into the same fund that lost my oldest son some serious change. Fortunately, the boys have about 15-17 years left on the investment and they'll be going on a full scholarship for something anyway - just like everyone's children.
I haven't put much in my Roth lately since I have a nice teacher pension fund going and am investing the rest in the old government (read: taxes and Social Security I'm not allowed to take because I'm a teacher), but I'm sure it's not pretty. Fortunately, I'm not even 30, so I have time for my formerly $15k there to regain value and grow a bit more.
I agree that investing in business is good and definitely is a good value for your money, but diversification never hurt anyone.