Just by converting to another format.
The PDF format is not really a total eBook format and even with text PDF's the reflowing engine in the 505 makes a hit and miss success with reflowing the text to let that be seen in a smaller screen that the one the PDF was build to be shown (example A4 PDF in a 6” screen).
One another example is the Adobe Acrobat reader for Pocketpcs (
http://www.adobe.com/products/acroba...p2_mobile.html) does a much better work in reflowing text then the one in the Sony!