KPager gets installed automatically with KDE in its KDEbase package since version 1.1
KPager is a core application of the KDE project http://www.kde.org. KPager can be found on the KDEbase package, which is at ftp://ftp.kde.org/pub/kde/, the main ftp site of the KDE project. You can also download it from any of the many ftp mirrors whose list is at http://www.kde.org/mirrors.html.
Additionaly, KPager has a homepage where you can follow its development, see some information about it, some screenshots, etc.