One of the Facebook features I had always hoped for was the ability to edit comments. I can't tell you how many times I've posted a comment and immediately realized I made a typo, but with the comment submitted there was no way to fix it. Sure you could delete it and re-post, but that's messy because it breaks the comment thread and also sends everyone in the thread a "ghost" notification to look at something that's no longer there.

A few days ago Facebook made a change, taking away the Submit button for comments. Now you use the Enter or Return key to submit and if you need to make a new line, you use Shift-Enter.

Yesterday I discovered that you now can edit a comment after you submit it, as long as you do it quickly. Just click the delete "X" in the upper-right corner of the comment and it will re-open so you can edit it or add to it. As best I can tell, you have about 20 seconds to make your edit. After that the only thing you can do is delete the comment. Watch the video for a demonstration.