Tip:
The PDF reader that came with the device doesn't scroll "pages" in any zoom level so you have to press the center navigation button to get out of full screen, finger tap on the arrow at the bottom to go to next page and then press the center button on the navigation pad to get to full screen again. Evince PDF reader allows page scrolling with finger touch but it is not very stable for large PDF files and slow in rendering pages. Between those two PDF readers, I get most of my PDF eBooks covered. If you rotate right in Evince PDF reader, you can scroll pages by touch flick like iPhone photo or weather application.