Try out the new Beta test wiki at http://pbwiki.com You will be able to do this by checking “Yes please make this a PBwiki test wiki” as step 3 when you are signing up for a new wiki.
The layout, design, and features of this test wiki are some of the best I’ve seen. You can send pbwiki feedback and comments on this test version. I hope they get the production version of this out soon, as I think it is a huge leap forward for pwiki. Try it out and let me know what you think.