@Hawkee it would be nice to see the option of having a daily update (when required) via email rather than have an email each notification; I like getting the emails, but sometimes I feel they are too often! Another option would be to only send one email per comment thread/post/image/etc until you've logged in again? Just throwing around ideas :)
Your idea sounds so logical like a Swiss watch ... in the sense that you have specific ideas about how it should be sent the notification. I like the real-time notification also because I do not come in large numbers and then I'm curious, how do? There should be more options ... ^_^