Please, please, please ...

...can someone who is more of a geek than me invent a way of subscribing to comments threads on other people's blogs!

I can subscribe to RSS feeds of practically everything on the web these days but none of the common blogging tools alert me when there has been an addition to a comment thread to which I have contributed or in which I am interested. Instead I have to keep remembering which threads I am interested in and have to keep checking back to see if anyone has added anything.