In reply to Wainers44:
I find that cheese (babybel is pretty tasteless, but as it is wrapped in wax it is really easy to stuff in a pocket or bumbag), sandwiches made with a wrap, cold pizza, pretzels and peanut butter all go down well, as do sausage rolls or pork pie if the race is very long and slow. I've heard lots of people say boiled potatoes with butter and salt are good too, but not tried them myself. I like to nibble on dried fruit and nuts or flapjack too
It is a bit of trial and error really, but I think the main thing for me is to choose things that I actually enjoy so that I actively want to eat them rather than having to force them down. I really dislike gels and whilst I usually have a couple with me, I would only ever choose them if I was in desperate need of an instant sugar boost.