I've recently started using related changes on sub-pages as an alternative. I've now got several, categorised watchlists - much easier to manage. Of course, it does mean that your watchlists are public - but there is still the usual watchlist as a smaller, private version.
An example of this - my Grammy watchlist is at: http://en.wikipedia.org/wiki/User:Sannse/grammy_watch
With the related changes at: http://en.wikipedia.org/w/index.php?title=Special:Recentchangeslinked&ta...
See: http://en.wikipedia.org/wiki/User:Sannse#Watchlists
--sannse