I have the cup holder like a few of the others. In fact it's the first accessory I add to any new to me bike - can't imagine a long ride without it. Coffee, tea, water, Gatorade ... Diet Mountain Dew.
Can't say I've really tried eating much on the go. Like some of the others, I've kept jerky, M&M's, other "pocketable" snacks around on the real long rides, but I prefer to stop eat, and enjoy the local "color".
Now, I did once see a gal riding passenger on a EGlide of some type eating a full McDonald's pancake breakfast thing (plate, fork, and all) while the guy driving had a McMuffin going down the highway.
I kept waiting for the pancakes to get some air time.