I just saw Edward Stanglers new post titled "
New databases may require catpatch" on http://www.orablogs.com - (broken link) orablogs. Ed mentions his catpatch.sql series of posts made to his blog a while back. I also mentioned them here. This new post is interesting as what Ed is saying is that if you create a database with the DBCA and use the pre-created database you may need to run catpatch.sql on a new database as the pre-created database files were made with 9.2.0.1 not 9.2.0.3 or later.
Also of interest is the fact as Ed points out that the database template files are simply zip files but with a different file extension (.dfj). This is a useful bit of trivia for anyone interested in internals and undocumented facts about Oracle.
From a security / versioning point of view this is an interesting
post from Ed that includes links to other posts of Ed's on similar subjects.