Computer Cartographer
This Minecraft mod adds a peripheral to ComputerCraft Tweaked that allows for interfacing with common mapping plugins (BlueMap, Dynmap, Pl3xMap, and Squaremap).
Information
Using the peripheral, you can dynamically draw POI (including custom icons), lines, circles, rectangles, and arbitrary polygon area markers to the mapping plugin of your choice.
You can create pathing previews using line markers, add real-time GPS pins for turtles on the move, or (if you have a mod with an entity sensor peripheral) put all the mobs in your area on the map.
See the wiki for usage details.