How to create a Broadband connection (pppoeconf) on my Android phone?
WIFI PPPOE by cnDDU is an app that allows you to make a PPPoE connection from your phone over a wireless connection:


  ...main purpose is for user
  to make PPPOE connection via WIFI, e.g. dialing through ADSL Modem
  with user name and password provided by some internet ISPs. This app
  makes the Android devices be able to connect to Internet directly via
  PPPOE dialing through WIFI, and no need for another WIFI Router any
  more.


Note that a rooted phone with Busybox installed is required to use this app.

There are also a number of other similar apps available in the Play Store now, some free, some not. They all currently seem to require a rooted phone.

(answer rescued from deletions)