Brian Greene does a pretty good job of explaining all this in the Elegant Universe. If you're into this kind of thing, check it out.
You can only move relative to another object. You may even move fast relative to one object and slow relative to another, meaning your clock ticks at a different rate relative to each of those objects.
There is no absolute clock - you can only compare your clock with someone else's clock.
Look, I'm only a layman, but from what I understand, the speed of light is the absolute clock.
I was refuting the idea of the speed of light as some sort of master clock.
But yes, the actual speed of light always looks like the speed of light.
The 'what' in "So what looks like 90% of the speed of light to you, can look like 10% of the speed of light to someone else." is referring to something travelling slower than the speed of light. A train or bullet perhaps. In different reference frames it can be said that this train/bullet is travelling at different percentages of the speed of light.
That's why it gets weird.
EDIT: To illustrate this, lets say we're sitting on the earth watching an astronaut. Relative to our position, he is travelling at 1/2 the speed of light. Now, some joker decides to shine his laser pointer at the astronaut. From earth we see the laser beam^ blast past the astronaut at .5c (.5c + .5c = 1c, the speed the laser light is traveling).
NOW! from the astronauts perspective! Instead of seeing the laser pass him at .5c, he sees it pass him a nice proper 1c. weird, but it's how the universe works.
^reflecting off spacedust of course :P
But the speed of light can only be measured relative to YOU
That's still wrong, though. The speed of light is an absolute; it's not My Speed + the Speed of Light.
The person I was who originally responded to me (ars) was trying to say that motion in space is impossible because it's always relative -- apparently even to the speed of light. That's not true; motion is relative to the speed of light, period. And what I had been trying to express (however badly) was that the faster you move relative to the speed of light, the slower you move in time.
I think ars was just in a nitpicky mood and was fixating on the particular wording I chose.
You can only move relative to other objects.
No matter how fast you go, if you measure your speed (relative to something else of course) you would measure a speed lower than the speed of light.
Elsewise, from a greater distance you will be able (assuming you have the means) to escape the gravitational pull of the black hole as you would any other object of equivalent mass.