It seems that there are a few topics that come up over and over, such as Things to do in SF, Cheap Legal advice, or Credit Card processing.
I know that PG is working on search, but it might be worth while to add a Best-of-HackerNews link, which includes some of the discussions that people who are just tuning in might want to catch up on.
A Frequently Submitted Questions category might fit the bill. The Hacker News Suggestions link could also go there, tacitly encouraging people such as myself to post new suggestions there, rather the main forum.