Printcraft is a Minecraft server that allows you to download and 3D print Minecraft models. You can either download and print the models on your on 3D printer, or have them printed and delivered online.
The Printcraft folks also make available a plugin for the multiplayer Bukkit server for Minecraft. Of course, the Bukkit server project is largely dead and Mojang apparently has no real interest in supporting the vast community of multiplayer server mods. It’s a shame that people working in their spare time are able to do more with Minecraft than Mojang with all its millions and licensing deals.