If you're a poor man like me, then you are pretty much stuck with a modem as your hardware for telecommunications. If you are in this boat, then PPP is pretty much the choice for serial-line TCP/IP WAN connectivity.
If you are rich, then you have a T1 or better running into your pad, and will never need to deal with PPP.
Most modern Linux distributions make setting up PPP a snap. Just RTFM and you'll have it done in 30 minutes.