Suggestion Thread for Command Blocks?

Hi guys. As some may know, I love working with command blocks and finding new ways to make stuff in Minecraft. With the new commands and features in 1.8, there are so many new possibilities. However, I can't always think of something to invent. So, if any of you have an idea for a feature/device [b][i]OR[/b][/i] know of a website/subreddit for ideas, please tell me! Please, no minigame suggestions unless they're [i]very[/i] tiny like my Rock Paper Scissors game because I already have a minigame project in the works. Thank you for reading!