I'm a DM, and recently I've been throwing around the idea of using Minecraft to build immersive puzzles and dungeons, so I started working on a mod with some useful DM tools. Depending on how much interest I see here, I might take this a bit farther. I've laid a fair bit of groundwork, but only have one major feature to show so far.
Dynamic Item Builder
The dynamic item builder lets you create custom items on the fly. Currently, you can give them a name, a description, and you can drop an existing item into the slot on the left to copy its sprite. I play to expand on this further in the future.
Any thoughts? Suggestions? Ideas? I'm mostly looking to gauge interest right now.