You can search for sites based on keywords. We maintain a whole site for this purpose, sites.fed.wiki.org.
Just visiting this page readies your browser for site searching. Wiki will load the sitemap of the sites.fed.wiki.org site after seeing this reference:
Catalog of federated wiki sites with domain names for page titles and brief descriptions tuned for search.
Try searching for hangout to find minutes from our chats.
Try searching for pattern for pattern language sites.
You can add a similar reference to your own pages to keep this index close at hand.