The simple answer is no, you cannot store driver jar files in your
webapp's .war file unless you want to setup and manage your own database
pool. Basically tomcat's internal classloader has to have access to the
driver in addition to your webapp which is why it has to be in
common/lib to begin
With Tomcat 5.5 you can now define things like JDBC DataSources in
META-INF/context.xml in your war files. JDBC DataSources need
drivers, and obviously they can still be stored in common/lib, but
given that they are defined, or rather their use is requested,
through the war file, can the driver