In a new entry today, Christopher Jones points out a guide to installing Oracle XE on a Ubuntu system, including PHP.

This needs no further description from me. I notice it says you need a static IP. I have a (nearly dead) laptop with the PHP/Oracle XE/Ubuntu stack working fine with a dynamic IP. Check out the references too. There are some good tips on the Ubuntu Forums link. Anyway, give it a whirl.

The guide breaks the installation down into a series of five steps, the last of which is testing the PHP installation with a simple Oracle connection.