I definitely get sweet overload on long rides - all that sweet drink mix, sweet bars.... I like to have some plain nuts or a bit of beef jerky - that little hit of salty protein really hits the spot sometimes. Another nice thing I've encountered on organized rides is salted boiled baby potatoes. Wrap them in foil and they keep fine in your pocket. I've heard great things about Alan lim rice cakes too - haven't tried them on a ride, but a bowl of scrambled eggs with rice is great before a long ride.