It looks like Miguel made a similar comment on the wiki two days ago. The additional suggestions that I see don't really reflect what I was thinking.
Most important is that the directory remain up-to-date. It is a big red flag to find a list that has old links. The only way to ensure this is to have local sites publish information, which can be grabbed on occasion.
Second, it seems like it would be better to create a new package to collect and publish the info, otherwise sites will need to update their APM for the new functionality. The new package will probably develop more rapidly than the APM. Also, information will probably come from more places than APM, and the package might depend upon non-core packages, which the developer might not want to install just to get the necessary APM package. Maybe the design of the websites-db package would satisfy the collect/update/publish functions.
Third, a separate package would run at OpenACS.org to grab the published data and make it available to promote the listed sites and the usefulness of OpenACS.
