Whoa... mind blown. I never noticed that feature before. Thank you Wise Weasel. (Not that I would up vote a post just to save it. but it is nice to know I have a list of all articles I've up-voted.)
+1 on having a "save" feature. However, I would shy away from using the term "flag" as a way to get something into the saved list. Flagging a post is already available and has a very different meaning.