Here's my (almost) completed fully integrated vBulletin gallery hack. It is fully templated and uses the existing forum system and thumbnailing functions. I've documented it, just need to write the user gallery script, beta test it for a week or two, and it'll be ready for release over here. Will be working on feeds for a number of vBulletin portal software systems next. I will also be writing an oekaki add-on, allowing users to draw pictures using java apps.
I have designed it so that it's fully customisable and expandable, you can plant thumbnail summaries around your forum structure (Latest Images in this example) that pull attachments from a specified list of galleries, and also create subgalleries.
The advantage of this system is that it uses all the functions of the forum system, allowing you to easily specify permissions, etc.
Link:
http://www.christiananime.net/forumdisplay.php?f=53