Rentry.co is a pastebin/publishing service with markdown support, preview, custom urls and editing. Fast, simple and free.
Url: Optional Url can be set. It goes rentry.co/HERE. If no Url was set then random Url will be generated automatically.
Edit code: Optional edit code can be set. It can be used to edit the entry later. If no edit code was set then random edit code will be generated automatically. Generated edit code will be shown to you only once, so remember it or save it.
Command line: Want to paste markdown from command line? Use this: https://github.com/radude/rentry