I have a macbook pro-several years old. I read this thread and most all these don't work on mine?!?! I want to go to bottom of all text (like on Windows Page up/down keys...BOOO!)
Mine works with command and the down arrow.
For 'dummies' like me: that would be the 'command' key on either side of the space bar and the arrow key in the right hand lower corner of keyboard, the arrow pointing up or down (not left or right).
There are some other condensed helpful tips at
http://www.danrodney.com.
Now for Iapino-who said you tried cmd+arrows---I don't know why it didn't work for you.
I have the new Mountain Lion OSX 10.8. This seems crazy to me-especially for Apple-that it would work differently for everyone. So come on you Mac Wizards--don't look down on us 'noobies' like we be 'gone!'