1) You may want functionality similar to saved articles but with subcategories for organization ("saved articles" has no subcategories, it's just a list). You can let people add existing articles from your directory into their personal articles list and its subcategories using this template code (a good place to put it is in the article bit, Admin Panel -> Themes -> Manage Templates -> "Sub-Templates" -> "Article Bit"):
<IF {TID} does not contain albums>
<form action="albums.php?add={LINKID}" method="post">
Add to <select name="subalbumid">{THISMEMBERALBUMLIST}</select>
<input type="submit" value="Add" >
</form>
</IF>
<form action="albums.php?add={LINKID}" method="post">
Add to <select name="subalbumid">{THISMEMBERALBUMLIST}</select>
<input type="submit" value="Add" >
</form>
</IF>
Or if you don't want to involve subcategories a simple link:
<a href="albums.php?add={LINKID}">Add this article to list</a>
To allow people to remove a article from their list, place this by it:
<IF {TID} contains albums><a href="albums.php?todo=remove&linkid={LINKID}&catid={LINKCATID}">Remove</a></IF>
Thanks to the conditionals, you can put these in the article bit and the add form will only show outside of the personal articles list while the remove link will only show inside the personal articles list.
2) You may want to let people add new articles that aren't in the directory. This is mostly useful for WSN Gallery, where members can have their own personal albums of their own images which aren't mixed with the site's images (you can even use your WSN Gallery as an add-on for a forum giving forum members each a gallery, when integrated with the forum member system). You may perhaps find use for it in the other scripts too.