Version 0.2.1 was released just yesterday. To get a working copy of Gnome-ppp, you will need a modem, the pppd daemon and the wvDial software (stock Slackware has a problem with wvDial, but fortunately a patched package is available).
The application greets you with a small window asking you username, password and phone number to dial out. Clicking "Setup", it will load a window with four tab views each one with preference items.
You can select your device (analog or USB modem and ISDN modem -- not sure how this would work with an internal ISA or PCI modem card but external 56k modems work), the speed you want it to connect to, speaker's volume, initialization strings for those who understand the modem tongue, up to 4 phone numbers just in case a phone number is busy (with prefix support), number of dialing attempts, DNS info (automatic DNS also support by default), and even more options on the last tab view where you can tell the modem to auto-reconnect and to minimize in the notification area upon connection.
What I love about this application are two things:
a. It gets to the point with easy to understand options.
b. It follows the HIG as much as it is possible, making the app look clean and well-thought.
For the future the author is reading support for multiple accounts (by using a wizard for new connections).
The application works really well and it looks good despite its 0.2.1 version. It wouldn't be stretched out suggesting to the author to propose the software for inclusion with Gnome 2.8 (if the Gnome project doesn't mind the wvDial dependency). This is a worthy application.