I was recently reading an article on the wizards website about "living in a flying box" which made a mobile and invincible stronghold...the poster mentioned a trick involving Mindswitch and Polymorph any Object, which allowed the caster to become the stronghold...my googlefu is failing me ATM

so, i have two questions:
1. how does the mindswitch and polymorph any object trick work?
2. are there any other interesting tricks like the one above that the playgrounders know?