I think the Wiki option makes sense since it is a publishing tool and allows for community editing (or not, depending on how you manage the settings). In addition to PBWiki you can check out MediaWiki (http://www.mediawiki.org/wiki/MediaWiki) and if either meets your needs. Google Docs are great but might not be as effortless to organize and use. I sense from the word "community" that you might have a range of tech savviness, so you'll want tools that are intuitive and inviting.

You might also check the document and project management tools like Huddle, which has a free version for small projects (http://www.huddle.com/plans-pricing/). The cheapest version of Basecamp (http://basecamphq.com/signup) is $50/month. I've participated in many online projects and find Basecamp to be a lifesaver in managing large numbers of documents, authors, reviewers, and deadlines.

Good luck with such a cool project!

Google blogs (Blogspot) have an option for private access.

This woman recommends Google Docs:
http://food.thefuntimesguide.com/2009/10/recipe_organizer_software.php

Here is a Wiki service that might work for the solution I described:

http://pbworks.com/

My way you might be able to do this is through a hosted wiki, a la Wikipedia. You could have a private wiki and grant access to just your family members or friends. Each page a recipe and you could inter link them. Just one idea.