zoho wiki or pb wiki?
I looked at both pb wiki and zoho wiki and like the latter better. As a matter of fact, zoho offers more tools than just wiki, such as chat, polls, group mail, database and reports, project management, and web conference.
I created a zoho wiki called Gateway to China (http://gateway2china.wiki.zoho.com/) and added a page there called "Cities Worthy a Visit). It is a short list and will be expanded.