Please provide more tools to help users moderate their own comments. In particular, I think the following features are sorely needed:

1. The ability to delete your own comments indefinitely, instead of having a window of only a few hours within which to delete your own comments.

2. The ability to flag your own comments for moderation.

I suppose one possible reason for not allowing comment deletion after a certain amount of time is that it forces people to really only make high-quality comments, otherwise they'll be downvoted and they won't be able to do anything about it after a few hours.

But if you're trying to improve the quality of Hacker News threads with high-quality comments, then I argue that it's counter-productive to force low-quality comments to remain by not allowing users to self-delete them after `X` hours.

Both Reddit and Stack Overflow allow users to delete their own comments indefinitely. Heck, Stack Overflow even encourages you to delete your own comments, if they don't contribute useful information to a post.