In my road bike's saddle bag is a spare tube, a patch kit, and 2 tire irons. I like to keep ID, cash, and cellphone in my jersey pocket, in the unlikely and unpleasant event that I am physically separated from my bike. For longer rides in your mentioned range, I'll throw a gel or two in my pocket. Maybe a Cliff Bar or something more substantial to gnaw on.
Oh, and the saddle bag is a Pedros bag - made from recycled inner tubes. Very small, very minimalist, and I quite like it.
2007 Seven ID8 - Bontrager InForm
2003 Klein Palomino - Terry Firefly (?)
2010 Seven Cafe Racer - Bontrager InForm
2008 Cervelo P2C - Adamo Prologue Saddle