There is already the personal nodelet. If you have
it turned on, a list of your bookmarked nodes is
visible with every pageview. The node currently
being viewed can be added with a single click.
Some shortcomings of the personal nodelet are that
it does not allow any kind of reordering or renaming
(as far as I know).
If that is a problem, you can use your scratchpad
instead; a link to add a node to the scratchpad is also found
in the personal nodelet. The advantage of the scratchpad
is that you can edit it, and make it public if you
desire. The disadvantage is that unlike the personal
nodelet, it isn't included with every pageview. Still,
one of the two should be capable of providing the
functionality you desire.