Minecraft: How to turn your portals on and off
Channel: WubbiConcepts
Date: 29/01/2012

To turn your portal on you can use the new fire charge item which got added in the new snapshot. Search for it, there are many examples already.

To turn it off you need to destroy at least one of the 6 portal blocks. Therefore i use my bedrock-destroyer. It's a block transmuter design which i created especially for converting the data values of pistons.

Tutorial: http://www.youtube.com/watch?v=OltSNjel0xg
New improved version: http://www.youtube.com/watch?v=0F0ImIHLQVY