The custom types/taxonomies feature of WP 3.0 is a neat one. I can think of a few ways to use the duo: to display projects, a portfolio, or a gallery. What else can custom types and taxonomies be leveraged for?
Custom types can be leverage for anything that can be repeatable. So as you said a gallery or portfolio would work very nicely. I've already used them on a few different projects:
- Employee Roster
- Callouts for the homepage
- rotating sliders.
Other ideas are:
- products for a commerce site—The custom taxonomies would make for some powerful option for each product.
- For custom sidebar content. Y
- An Ad manager.
The possibilities are really endless. Anything that can be seen as a collection is really what this is for.
How about a forum? Have a look at http://justintadlock.com/archives/2010/07/16/a-wordpress-forum-plugin-using-custom-post-types and a couple of other posts on taxonomies on that site. Justin wrote the Hybrid theme. He is also a core contributor.