the pocketxpdf can be found here.
http://pocketxpdf.sourceforge.net/
the description on the site reads:
PocketXpdf is a no-frills viewer for native PDF files for the Pocket PC platform. The rendering engine is a port of Xpdf. The program is currently in an early development stage. PocketXpdf has been tested on an ASUS MyPal running Windows Mobile 2003 and on a Dell Axim X51v running Windows Mobile 5. It has not been tested on earlier versions, so it cannot be guaranteed that it will work on these systems. The Screenshots on this page are taken from the Windows Mobile 2003 SE and Windows Mobile 5 emulators provided with Visual Studio.
when it says 'no frills' it definately means than. it can zoom in/out, and you can map your d-pad buttons how you want. other than that. its very basic.
it has a landscape mode too which may be cool. the install is really easy. just unzip the file and put it somewhere on your ppc. i'm running it from my SD card and it works fine.
party.