StreamOfTheSky
Adventurer
As everyone's said, D-Door lets you escape a grapple. IME, that's what it's used for ~90% of the time.
As a side-note, back when I was trying to re-make the grappling prestige class from complete warrior (name currently escapes me), one of the class features was the ability to forcibly hold on (after a difficult grapple check) and count as part of the enemy caster's gear if he tried to teleport / plane shift / etc... out of a grapple with you, causing it to fail if that would make the spell fail. It'd be cool to have such an ability somewhere in the game. then you'd have casters putting up fire res just to shift to the plane of fire and make the grappler pay for hanging on...ah, hilarious!
But the caster must choose to take the other creature(s) with him, and the creature(s) must be willing to go.
As a side-note, back when I was trying to re-make the grappling prestige class from complete warrior (name currently escapes me), one of the class features was the ability to forcibly hold on (after a difficult grapple check) and count as part of the enemy caster's gear if he tried to teleport / plane shift / etc... out of a grapple with you, causing it to fail if that would make the spell fail. It'd be cool to have such an ability somewhere in the game. then you'd have casters putting up fire res just to shift to the plane of fire and make the grappler pay for hanging on...ah, hilarious!