I've often found myself posting a comment on someone else's blog only to realize I made a spelling or code mistake after I've submitted it.
So, I got to thinking. Wouldn't it be cool if a user could edit their own comments?  Clarification: I'm referring to non-WordPress registered users here. [/edit] I've been thinking about it on and off for the past couple days and here's the features and methods that I've come up with. Please, by all means, contribute ideas.
- Only allow editing for X amount of time.
Can be turned off to allow editing of any comment (I'd allow like 15 min tho or something personally). This is server-side -- just takes current time, subtracts comment time, compares to allowed edit time.
Two ideas here. First, create a table that stores the comment ID along with a RANDOM string that is placed in both the DB and a cookie on the user's machine. This (hopefully) only allows the original poster to edit the post. Exploitable possibly? Not sure.
Other idea - authentication via IP address. Only allow a user with the IP address matching that of the comment to edit the post. This would only be acceptable for if there was a "short" edit time limit, otherwise someone else could get the IP, the user's IP address could change, etc.
- Only allow X edits per comment
You don't really want a comment being edited 1000 times, do you?
- Log changes?
What if someone were to post a racist comment and then like a minute before their edit time is up, change it to "I like bunnies". You'd probably never know about the racist comment. So logging, or maybe some slick way of not allowing like erasing of a comment's content? Dunno. Maybe just allow additions... or strike out any removed content like this. Old comment:
This is the originla comment. This is a sentence. I msipeled some wrds.
To like this?
This is the <del>originla</del> original comment. <del>This is a sentence.</del> I added this sentence. I <del>msipeled</del> mispelled some <del>wrds</del> words.
 Seems these forums don't allow
<del>, so just use your imagination. [/edit]
Maybe some styling on any added content.
Any other thoughts on this and ways of implementing it?