There are many good tools available for configuring and using PPP on Linux. This document will try to cover some of the more popular ones, including:
kppp A PPP setup and dialer tool for KDE.
WvDial Another PPP driver for Linux, with an emphasis on simplicity.
RP3...(short for RedHat PPP). It is a simple configuration program with a "wizard" interface- it asks a series of questions.
Linuxconf A generalized tool for configuring and managing your Linux machine, it has a section that helps configure PPP.