Hi Austin,
I tried to reproduce your error message and I get the following Message when I delete the RessourceLink-Line of the context.xml-File:
org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'
This seems to be the same error message you get so I think the problem is somewhere inside this topic. I checked my IDE (Netbeans 4.0) to find out that the content of the META-INF/context.xml file in each web-application is copied to a xml-File in Tomcats conf-Folder (Maybe there're also differences depending on the tomcat version, I've got Tomcat5). This xml-File's name is always the web-applications name.
For you this would mean that there has to be a file ora.xml in the folder conf/Catalina/localhost/. I'm not able to say if my IDE creates this file or tomcat does. Maybe you can have try.
In your posting you wrote that you put the context.xml-File in a folder called META-INT. I guess this was just a spelling mistake because it has to be in META-INF. It would also be helpfull if you could post the source of context.xml-File.