Ok basicly this is an extension towards the "fuse players together exploit" released by RaoV.
How does it work?
First you use RaoVs exploit in order to fuse together. Make sure the one that stays in his/her Mechano-hog is a mage / druid / dk or any class that has some sort of teleport option. The one that jumps can be anyone.
Once you succesfully fused together, the teleporter is able to cast any teleport and simply takes the one he fused with, with him. I've tested this myself with a mage / druid and those were succesfull. Unfortunately I was unable to test this with a dk's deathgate so perhaps someone else able to confirm this.
What doesn't work:
You can't hitchhike battleground invites. We tried this with the idea to hitchhike with a lower lvl (hehe), but it didn't work.
Ideas to test:
Fuse together with a low-lvl and get summoned to icc (or any other raid).