Re: Saving post
Do you want to "save" it so you can go back and check it, or participate in it later? If so, just bookmark it, or save it as a watched thread.
If you want to "save" it as a future reference item, you can save it to your computer as an archive file.
It will take a snapshot of the thread and save it, you will be able to view it, but not add to it or edit it from the archived file.