So I finally got the Cloud in a Bottle accessory and I've noticed an interesting effect. It pertains to the world ceiling and a combination of accessories, the Cloud in a Bottle being another contributor. If you have Rocket Boots, Hermes Boots, Cloud in a Bottle, Armor or accessories that increases your flight time and maybe the Shiny Red Balloon and the Lucky Horseshoe, you can use the ceiling to travel indefinately across the map (or as far as you can go before your wrist cramps up from pressing the spacebar repeatedly).

The checklist to do this is thus:

  1. have a long flat surface, maybe in the air if you have low amounts of Mana.
  1. Run as far as you can until the Hermes Boots activate.
  1. Double Jump and then activate the Rocket boots and ascend until you bump into the world ceiling
  1. Here's where it gets tricky, because you have to press spacebar immediately, otherwise you might fall too far and the doublejump won't propel you high enough to hit the world ceiling again. If you hit it fast enough you'll keep hitting the ceiling and with the Hermes boots equipped you'll keep running.

For some reason hitting the world ceiling isn't like coming to a full stop, so the hermes boots will continue to be active as long as you are in the air!. You can also use Necro armour and a few anklets of wind to substitute for the Hermest Boots.

Video Proof: