Bright Water (random_stuff:bright_water), a water-like node that is set to the max light output. You cant drown in it, has 0 viscosity and has the same spread as lava.
Wings (3d_armor:wings), a power-up that utilizes the 3d_armor mod to give you reduced gravity and an immortal health status. Downside is that to craft it you need an item rarer then diamonds or mese.
Spring Boots (3d_armor:spring_boots) also uses the 3d_armor mod to let you jump super high and increases your speed. This bit of armor is equivalent to bronze in its strength and is a lot easier to craft the the wings. Beware of using this with wings though... undesired results may occur(reverse meteor)

Weird Soul Thing(random_stuff:soul) This very creatively named item is used soully for crafting wings. It is found only in The Sole Stone ore block that is naturally occurring but rather rare
The Sole Stone(random_stuff:stone_with_soul) A naturally occurring ore stone that contains a soul for crafting wings. The texture was made from the Soul Thing with the alpha set from mese ore... looks odd though.
Springs(For Bouncy Things) (random_stuff:springs) crafted itself from 3 steel ingots this is used in conjunction with steel boots to make spring boots.

/crawl enables a head only mode that alows you to go into 1x1 areas
/stand disables /crawl and returns the player to the normal character(3d_armor character model is enabled if that mod is installed)