If you want to change content, taxonmy, users, ... in the future, you can set a bookmark. So you can see in a view the items you selected.
The module has 2 built in types of flags; Bookmark for content and Follower for users.
You can add a new one yourself eg. A to do list
The nodes of the selected content types have now a link in the display mode (as administrator)
There is a view that shows all the bookmarks (of the bookmark type. The other ones you have to make yourself).
Add a flag type if needed...eg TO DO