Thanks, Debra. I do most of my online shopping at Amazon and other companies with a physical presence in California, so I'm accustomed to paying sales tax on my online purchases, but I've never been charged tax on the shipping or any other services -- just on the merchandise.
Unless the laws have changed, I suspect that my friend was not supposed to charge a Minnesota customer sales tax. I wonder if the laws have changed here. California is hurting for revenue, so it wouldn't be surprising.