I have finally got around to adding a feature which allows commenters to ask for followup comments to be sent to them by email. The commenter can opt whether or not to receive these emails, and before any emails are sent the address will need to be verified, this is to prevent the site being used to spam people. This is on a post by post basis. People who subscribe using this feature can cancel a subscription for a particular post, or for the whole site, by following the instructions in the email. This should prevent people becoming deluged in the unlikely event that a comment thread 'takes off'.
This is in addition to the XML feeds provided for each post.
Please report any bugs by commenting upon this (or indeed any) post, though this post is the best place!
Remember, if you're an 'unknown' poster the comment may enter moderation. Blame the spammers for this. I will 'whitelist' regular commenters to bypass this feature. If that applies to you, and I have yet to whitelist you, please comment here and I will address this).