I don't know if this can be classified as an idea. Still, lately when I try to edit a post and I have a URL embedded in it, the URL appears in a weird format and sometimes it can appear multiple times, depending on how many times the post has been edited. I am not sure when this started happening. I think it's there for at least a month now.
I don't know about other people, but I edit my posts quite often. I do try to post the best I can from the beginning, but sometimes some additional ideas come to me and I want to avoid a different post for clarifications, especially if the additional post needs to include a lot to point to the exact point in previous message where the additional material applies. To handle this issue I copy paste from my initial post instead of using the ready old text of my post provided by the "edit" facility.
And just to make this post a little bit more of an idea: I think a sign that says "this post has been edited by author" would be helpful for readers to realize a post they read earlier has changed. Sometimes people say they edited their posts and sometimes they forget to mention it or do not think the change is very important.
p.s. It seems I am editing even this one! Thankfully I had no URLs embedded. ;-)
Each post has a timestamp on it (e.g. Feb 21, 2009, 4:48pm PST). There could be another timestamp that says: last edit at e.g. Feb 21, 2009, 4:58pm PST. Posts cannot be edited after some time passes (30 min), so the additional timestamp could take advantage of the old timestamp if this makes the associated storage overhead lower.