Anyone ever watch the show Sliders? Ideas: Use a specified item as the controller. Set a random amount of time allowed in the world before the portal activates. The portal would disappear from the world in a specified amount of time. You should be spawned at a random warp/world/coordanates/etc. There would be a customizable list of the places to be spawned. If you miss the portal or lose your controller you are stuck in that world or place. Right Clicking a big enough open area would spawn the portal.
