Hey,
i had the Idea to make C4 in Minecraft in the new 1.8 Snapshots. All you have  to do ist copy this into a CommandBlock and givt the Comandblock power. You will get a Book with Controls in it.

--
Copy this in to CommandBlock:

 /give @a written_book 1 0 {pages:["{\"text\":\"\",\"extra\":{\"text\":\"Plant C4]\",\"color\":\"dark_purple\",\"bold\":\"true\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/summon Arrow ~ ~ ~\"},\"hoverEvent\":{\"action\":\"show_text\",\"value\":\"Plant c4 to your current Position\"}},{\"text\":\"      [Detonate]\",\"color\":\"dark_blue\",\"bold\":\"true\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\" /execute @e[type=Arrow] ~ ~ ~ summon PrimedTnt\"},\"hoverEvent\":{\"action\":\"show_text\",\"value\":\"Detonates all C4\"}}]}"],title:C4 in Minecraft,author:DavidStyler10}

--

Have fun with it and tell me your opinion in the Comments. Want some more things like that in Minecraft?

~DavidStyer10