Clif Shot Blocks are like Clif Shot energy gels, only in solid form. They're basically caffeinated gummy lollies (though some flavours just have sugar and electrolytes without the caffeine). The orange flavour is quite pleasant to taste and has the equivalent of half a shot of coffee per "blok". I find they help me to keep going during long runs, and are more convenient to carry and quicker to consume than energy drinks or gels.
They are available at sporting goods stores for about $5.95 per 60g pack (6 bloks, or two or three workouts worth).