Profile: My Posts, My Groups, My Contacts
A common complaint around here is that it's hard to find your previous posts. From your profile, you can find your posts (blogs) and a list of groups, but not posts to groups or any comments.
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Forum Discussion
Once you comment, you should receive a notification in your Messages if people comment after you. Currently there's no way to receive notifications for conversations you haven't commented on (in other communities, this feature may be callled following, subscribing, or bookmarking a conversation).