Minecraft Realms, a server hosting service by Mojang, is released worldwide for the Mac and PC versions of the game. The service costs $13 per month and does not require setting up a LAN network or configuring IP addresses to start a server:
We’re proud to announce that Minecraft Realms for PC and Mac is now available worldwide! Realms is the easiest way for you to host a Minecraft world online. You and your friends can work on an awesome creation, adventure into the depths, or play one of our featured mini-games with just a few clicks.