What to do with portals?

What exactly can you do with a portal after modding? Sure, it looks cool but after placing 2 next to each other they disappear. Any ideas?

 

Well, if you modded nether, glow stone and soul sand you have no need for a portal at all.

 

Well I did that, I'm just curious to see what others did with it.

 

I think they make pretty cool windows as long as the window is only 1 square big.

 

You can place two diagnol from eachother.
P = Portal
B = Block

BP
PB

Tada!