One of the ways I'd like to extend the themes offered here is by packaging them or the child themes with new page templates.
The only theme that has exclusive page templates right now is the Options theme. It has:
no-sidebar.php
blog.php
archives.php
Each of these extend the functionality of your site if needed. Of course, page templates can be made for anything.
What are page templates?
All PAGES (not posts) default to the Default Template (page.php), which is all fine and good until you need to do some more custom work but not mess up other pages.
So, you create what we call a page template. Once you've created a page template, you can select it as the template for any page on your site. Now, that page will have different functionality (possibly a different style) than the rest of the site.
For example, the Archives template with the Options theme shows an archive of your posts by month. However, with an archive plugin installed (Smart Archives or SRG Clean Archives), you'll have an even better archives page.
But, we can do better. If we start thinking outside the box a bit, there might be some other great uses.
What can we actually do with these things?
Anything. It's basically a blank slate. You could set up image galleries, bookmark lists, or even implement popular plugins.
One thing that I do not like to see (and I see this often) is turning pages into a category page. That's what category archives are for. Honestly, don't ask me to set up something like that. It's pointless and creates duplicate content on your blog.
We do, however, have a three column page template tutorial here in the forums:
http://themehybrid.com/support/topic/options-and-a-3-column-page
It pulls posts from three different categories, which is kind of cool. Again, I'm not a huge fan of the category thing, but it can be neat if you have three categories to feature. Heck, you could even put other stuff in there besides categories.
What I'd like to hear from you
I'd like to hear some ideas!
I already know what I'd use page templates for. What I don't know is what you'd use them for.
One template I'd like to include in a few of the themes is an Authors template, which would create a list of all authors with biographical info and avatars. I have a tutorial on it:
http://justintadlock.com/archives/2008/06/09/doing-more-with-gravatars-authors-template-page
So, if you think you have a good idea for a page template (I hope something that would benefit many users), let us hear it.