Firefox Bookmark Update Indicator

[Joshua Lutes]

I'm wondering if anybody knows of an add-on for Firefox that would indicate
when a change has been made to a website that has been bookmarked.

RSS feeds are nifty but I don't like that live bookmarks are displayed as
folders in Firefox.  I'd rather that it be displayed as a single page that
notifies me, by changing color maybe, whenever the RSS feed is updated with
new content since the last time that I visited.  Maybe even be able to
associate normal pages with their RSS feeds so that I could go directly to
'em.

I guess, if nobody knows of this thing's existence, could you guess at how
tricky it'd be to code up?  And how possible.  I've never done a plugin
before, but I guess I could try.  They are done in javascript right?
Anyway, thanks for any infos.

Joshua Lutes