Wikipedia has an excellent method using a watchlist. The feature that Wikipedia is missing is mailing notification of changes on the watchlist. I think there have been discussions on Wikipedia's wiki (MediaWiki) about enhancing the watchlist to allow certain topics to be emailed on changes and/or emailing of the watchlist.
Watch topics I have edited/commented on
Wikipedia's watchlist also has a feature of automatically adding a page you edit to the watchlist (this is configurable in the preferences).
Another way would be to have a checkbox to 'watch topic' on the preview screen.