Comment editing/removal record
Short, concise description of the idea
Keep a record of the comment before it is edited/deleted.
Full description of the idea
Right now you can only delete comments so this actually applies only to that, but if there is ever a way to edit comments in the future this should apply to it too.
Give the owner of the journal the ability to specify that all comment deletions will be logged, basically put a link under the "Comment Deleted" string that links to the comment as it was before it was deleted. This is much like "No anonymous replies" or "Log IPs" in that it would cut down on harassing responses if the person knew that he could never delete the comment later. It would at least, perhaps, make him stop and think for an instant about whether he should be commenting or not.
This goes along with the very recent suggestion to disallow deletion of posts, and is also backed by the simple principle of not allowing the destruction of information.
An ordered list of benefits
I'm copying some points from alocin's related suggestion (except that I'm actualy ordering my lists :))
1. People abusing people won't get away with it
2. I'll be happy :)
3. It would preserve context for arguments in which people delete early comments.
4. It would make people stop and think about their comments/wording a little bit more.
5. It is the user's journal, he gets to allow people to come and comment or not, so he should also be able to demand that the integrity of the whole collections of comments in his journal be upheld, which the ability to delete/edit comments without a record subverts.
6. The principle that anything that could cause the destruction of information should be considered carefully. (this is cheesy, I know, but it's a good rule for guidance, I think).
An ordered list of problems/issues involved
1. I'm sure some people will respond that "They're my comments, I should be able to delete them", to which I would respond that if you knew you couldn't delete them when you posted you shouldn't have posted.
2. Some people might not post comments in journals that have this enabled, which is why it should be a journal preference.
3. Basically all the same issues that came with logging of IP addresses.
4. It would take more space to store, but I would imagine that the dumber of deleted comments would go down when people wouldn't be removing every trace of the comment anymore.
An organized list, or a few short paragraphs detailing suggestions for implementation
Same as logging of IPs? I don't really know. Just something to consider for the future.